Burden of proof (law)

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Burden_of_proof_(law)#Preponderance_of_the_evidence

In a legal dispute, one party has the burden of proof to show that they are correct, while the other party had no such burden and is presumed to be correct. The burden of proof requires a party to produce evidence to establish the truth of facts needed to satisfy all the required legal elements of the dispute.

The burden of proof is usually on the person who brings a claim in a dispute. It is often associated with the Latin maxim semper necessitas probandi incumbit ei qui agit, a translation of which is: "the necessity of proof always lies with the person who lays charges." In civil suits, for example, the plaintiff bears the burden of proof that the defendant's action or inaction caused injury to the plaintiff, and the defendant bears the burden of proving an affirmative defense. The burden of proof is on the prosecutor for criminal cases, and the defendant is presumed innocent. If the claimant fails to discharge the burden of proof to prove their case, the claim will be dismissed.

Definition

The term "burden of proof" is a party's duty to prove a disputed assertion or charge, and includes the burden of production (providing enough evidence on an issue so that the trier-of-fact decides it rather than in a peremptory ruling like a directed verdict) and the burden of persuasion (standard of proof such as preponderance of the evidence).

A "burden of persuasion" or "risk of non-persuasion" is an obligation that remains on a single party for the duration of the court proceeding. Once the burden has been entirely discharged to the satisfaction of the trier of fact, the party carrying the burden will succeed in its claim. For example, the presumption of innocence in a criminal case places a legal burden upon the prosecution to prove all elements of the offense (generally beyond a reasonable doubt), and to disprove all the defenses except for affirmative defenses in which the proof of non-existence of all affirmative defense(s) is not constitutionally required of the prosecution.

The burden of persuasion should not be confused with the evidential burden, or burden of production, or duty of producing (or going forward with evidence) which is an obligation that may shift between parties over the course of the hearing or trial. The evidential burden is the burden to adduce sufficient evidence to properly raise an issue at court.

There is no burden of proof with regard to motive or animus in criminal cases in the United States. The intent surrounding an offense is nevertheless crucial to the elements of the offense in a first-degree-murder conviction. This brings up the ethical dilemma of whether or not a death sentence should be imposed when the defendant's motives or intentions are the contingent factors in sentencing. However, in some cases such as defamation suits with a public figure as the defamed party, the public figure must prove actual malice.

Standard of proof in the United States

Burden of proof refers most generally to the obligation of a party to prove its allegations at trial. In a civil case, the plaintiff sets forth its allegations in a complaint, petition or other pleading. The defendant is then required to file a responsive pleading denying some or all of the allegations and setting forth any affirmative facts in defense. Each party has the burden of proof of its allegations.

Legal standards for burden of proof

Some evidence

Per Superintendent v. Hill (1985), in order to take away a prisoner's good conduct time for a disciplinary violation, prison officials need only have "some evidence," i.e., "a modicum of evidence"; however, the sentencing judge is under no obligation to adhere to good/work time constraints, nor are they required to credit time served.

Reasonable indications

"Reasonable indication (also known as reasonable suspicion) is substantially lower than probable cause; factors to consider are those facts and circumstances a prudent investigator would consider, but must include facts or circumstances indicating a past, current, or impending violation; an objective factual basis must be present, a mere 'hunch' is insufficient."

The reasonable indication standard is used in interpreting trade law in determining if the United States has been materially injured.

Reasonable suspicion

Main article: Reasonable suspicion

Reasonable suspicion is a low standard of proof to determine whether a brief investigative stop or search by a police officer or any government agent is warranted. It is important to note that this stop or search must be brief; its thoroughness is proportional to, and limited by, the low standard of evidence. A more definite standard of proof (often probable cause) would be required to justify a more thorough stop/search. In Terry v. Ohio, 392 U.S. 1 (1968), the Supreme Court ruled that reasonable suspicion requires specific, articulable, and individualized suspicion that crime is afoot. A mere guess or "hunch" is not enough to constitute reasonable suspicion.

An investigatory stop is a seizure under the Fourth Amendment. The state must justify the seizure by showing that the officer conducting the stop had a reasonable articulable suspicion that criminal activity was afoot. The important point is that officers cannot deprive a citizen of liberty unless the officer can point to specific facts and circumstances and inferences therefrom that would amount to a reasonable suspicion. The officer must be prepared to establish that criminal activity was a logical explanation for what he perceived. The requirement serves to prevent officers from stopping individuals based merely on hunches or unfounded suspicions. The purpose of the stop and detention is to investigate to the extent necessary to confirm or dispel the original suspicion. If the initial confrontation with the person stopped dispels suspicion of criminal activity the officer must end the detention and allow the person to go about his or her business. If the investigation confirms the officer's initial suspicion or reveals evidence that would justify continued detention the officer may require the person detained to remain at the scene until further investigation is complete, and may give rise to the level of probable cause.

Reasonable to believe

In Arizona v. Gant (2009), the United States Supreme Court defined a new standard, that of "reasonable to believe." This standard applies only to vehicle searches after the suspect has been placed under arrest. The Court overruled New York v. Belton (1981) and concluded that police officers are allowed to go back and search a vehicle incident to a suspect's arrest only where it is "reasonable to believe" that there is more evidence in the vehicle of the crime for which the suspect was arrested.

There is still an ongoing debate as to the exact meaning of this phrase. Some courts have said it should be a new standard while others have equated it with the "reasonable suspicion" of the Terry stop. Most courts have agreed it is somewhere less than probable cause.

Probable cause

Main article: Probable cause

Probable cause is a higher standard of proof than reasonable suspicion, which is used in the United States to determine whether a search, or an arrest, is unreasonable. It is also used by grand juries to determine whether to issue an indictment. In the civil context, this standard is often used where plaintiffs are seeking a prejudgement remedy.

In the criminal context, the U.S. Supreme Court in United States v. Sokolow, 490 U.S. 1 (1989), determined that probable cause requires "a fair probability that contraband or evidence of a crime will be found." The primary issue was whether Drug Enforcement Administration agents had a reason to execute a search. Courts have traditionally interpreted the idea of "a fair probability" as meaning whether a fair-minded evaluator would have reason to find it more likely than not that a fact (or ultimate fact) is true, which is quantified as a 51% certainty standard (using whole numbers as the increment of measurement). Some courts and scholars have suggested probable cause could, in some circumstances, allow for a fact to be established as true to a standard of less than 51%, but as of August 2019, the United States Supreme Court has never ruled that the quantification of probable cause is anything less than 51%. Probable cause can be contrasted with "reasonable articulable suspicion" which requires a police officer to have an unquantified amount of certainty the courts say is well below 51% before briefly detaining a suspect (without consent) to pat him down and attempt to question him. The "beyond reasonable doubt" standard, used by criminal juries in the United States to determine guilt for a crime, also contrasts with probable cause which courts hold requires an unquantified level of proof well above that of probable cause's 51%. Though it is beyond the scope of this topic, when courts review whether 51% probable cause certainty was a reasonable judgment, the legal inquiry is different for police officers in the field than it would be for grand jurors. It is also notable that in Franks v. Delaware, the U.S. supreme court held that probable cause requires that there not be "reckless disregard for the truth" of the facts asserted.

Examples of a police officer's truth-certainty standards in the field and their practical consequences are offered below:

• no level of evidence required: a knowing and voluntary consent-based encounter between police officer and another person
• reasonable articulable suspicion of criminal activity required: an involuntary stop initiated by the officer to briefly detain, attempt to question, and pat down outer clothing of a person of interest to police.
• probable cause of 51% truth or higher required that a crime was committed by a specific person : arrest and/or grand jury indictment of that person.

Some credible evidence

Some credible evidence is one of the least demanding standards of proof. This proof standard is often used in administrative law settings and in some states to initiate Child Protective Services (CPS) proceedings. This proof standard is used where short-term intervention is needed urgently, such as when a child is arguably in immediate danger from a parent or guardian. The "some credible evidence" standard is used as a legal placeholder to bring some controversy before a trier of fact, and into a legal process. It is on the order of the factual standard of proof needed to achieve a finding of "probable cause" used in ex parte threshold determinations needed before a court will issue a search warrant. It is a lower standard of proof than the "preponderance of the evidence" standard. The standard does not require the fact-finder to weigh conflicting evidence, and merely requires the investigator or prosecutor to present the bare minimum of material credible evidence to support the allegations against the subject, or in support of the allegation; see Valmonte v. Bane, 18 F.3d 992 (2nd Cir. 1994). In some Federal Appellate Circuit Courts, such as the Second Circuit, the "some credible evidence" standard has been found constitutionally insufficient to protect liberty interests of the parties in controversy at CPS hearings.

Preponderance of the evidence

Preponderance of the evidence (American English), also known as balance of probabilities (British English), is the standard required in most civil cases and in family court determinations solely involving money, such as child support under the Child Support Standards Act, and in child custody determinations between parties having equal legal rights respecting a child (typically the parents of a child who are divorced, separated, or otherwise living apart, assuming that neither has been found unfit). It is also the standard of proof by which the defendant must prove affirmative defenses or mitigating circumstances in civil or criminal court. In civil court, aggravating circumstances also only have to be proven by a preponderance of the evidence, as opposed to beyond reasonable doubt (as in criminal court).

The standard is met if the proposition is more likely to be true than not true. In other words, the standard is satisfied if there is a greater than fifty percent chance that the proposition is true. Lord Denning, in Miller v. Minister of Pensions, described it simply as "more probable than not." Until 1970, it was also the standard used in juvenile court in the United States.

Preponderance of the evidence is also the standard of proof used in United States administrative law.

From 2013 to 2020, the Department of Education required schools to use a preponderance of evidence standard in evaluating sexual assault claims.

Clear and convincing evidence

Clear and convincing evidence is a higher level of burden of persuasion than "preponderance of the evidence," but less than "beyond reasonable doubt." It is employed intra-adjudicatively in administrative court determinations, as well as in civil and certain criminal procedure in the United States. For example, a prisoner seeking habeas corpus relief from capital punishment must prove his factual innocence by clear and convincing evidence. New York State uses this standard when a court must determine whether to involuntarily hospitalize a mentally ill patient or to issue an Assisted Outpatient Treatment Order. This standard was also codified by the United States Supreme Court in all mental health civil commitment cases.

This standard is used in many types of equity cases, including paternity, persons in need of supervision, child custody, the probate of both wills and living wills, petitions to remove a person from life support ("right to die" cases), mental hygiene and involuntary hospitalizations, and many similar cases.

Clear and convincing evidence is the standard of proof used for immunity from prosecution under Florida's controversial stand-your-ground law. Once raised by the defense, the state must present its evidence in a pre-trial hearing, showing that the statutory prerequisites have not been met, and then request that the court deny a motion for declaration of immunity. The judge must then decide from clear and convincing evidence whether to grant immunity. This is a lower burden than "beyond a reasonable doubt," the threshold a prosecutor must meet at any proceeding criminal trial, but higher than the "probable cause" threshold generally required for indictment.

Clear and convincing proof means that the evidence presented by a party during the trial must be highly and substantially more probable to be true than not and the trier of fact must have a firm belief or conviction in its factuality. In this standard, a greater degree of believability must be met than the common standard of proof in civil actions (i.e. preponderance of the evidence), which only requires that the facts as a threshold be more likely than not to prove the issue for which they are asserted.

This standard is also known as "clear, convincing, and satisfactory evidence"; "clear, cognizant, and convincing evidence", and is applied in cases or situations involving an equitable remedy or where a presumptive civil liberty interest exists. For example, this is the standard or quantum of evidence use to probate a last will and testament.

Beyond reasonable doubt

Main article: Reasonable doubt

This is the highest standard used as the burden of proof in Anglo-American jurisprudence and typically only applies in juvenile delinquency proceedings, criminal proceedings, and when considering aggravating circumstances in criminal proceedings. It has been described, in negative terms, as a proof having been met if there is no plausible reason to believe otherwise. If there is a real doubt, based upon reason and common sense after careful and impartial consideration of all the evidence, or lack of evidence, in a case, then the level of proof has not been met.

Proof beyond a reasonable doubt, therefore, is proof of such a convincing character that one would be willing to rely and act upon it without hesitation in the most important of one's own affairs. However, it does not mean an absolute certainty. The standard that must be met by the prosecution's evidence in a criminal prosecution is that no other logical explanation can be derived from the facts except that the defendant committed the crime, thereby overcoming the presumption that a person is innocent unless and until proven guilty.

If the trier of fact has no doubt as to the defendant's guilt, or if their only doubts are unreasonable doubts, then the prosecutor has proved the defendant's guilt beyond a reasonable doubt and the defendant should be pronounced guilty.

The term connotes that evidence establishes a particular point to a moral certainty which precludes the existence of any reasonable alternatives. It does not mean that no doubt exists as to the accused's guilt, but only that no reasonable doubt is possible from the evidence presented. Further to this notion of moral certainty, where the trier of fact relies on proof that is solely circumstantial, i.e., when conviction is based entirely on circumstantial evidence, certain jurisdictions specifically require the prosecution's burden of proof to be such that the facts proved must exclude to a moral certainty every reasonable hypothesis or inference other than guilt.

The main reason that this high level of proof is demanded in criminal trials is that such proceedings can result in the deprivation of a defendant's liberty or even in their death. These outcomes are far more severe than in civil trials, in which monetary damages are the common remedy.

Another noncriminal instance in which proof beyond a reasonable doubt is applied is LPS conservatorship.

Standard of proof in the United Kingdom

In the three jurisdictions of the UK (Northern Ireland; England & Wales; and Scotland) there are only two standards of proof in trials. (There are others which are defined in statutes, such as those relating to police powers.)

The criminal standard was formerly described as "beyond reasonable doubt". That standard remains, and the words commonly used, though the Judicial Studies Board guidance is that juries might be assisted by being told that to convict they must be persuaded "so that you are sure".

The civil standard is 'the balance of probabilities', often referred to in judgments as "more likely than not".

The civil standard is also used in criminal trials in relation to those defenses which must be proven by the defendant (for example, the statutory defense to drunk in charge that there was no likelihood of the accused driving while still over the alcohol limit). However, where the law does not stipulate a reverse burden of proof, the defendant need only raise the issue and it is then for the prosecution to negate the defence to the criminal standard in the usual way (for example, that of self-defence).

Prior to the decision of the House of Lords in Re B (A Child) [2008] UKHL 35 there had been some confusion – even at the Court of Appeal – as to whether there was some intermediate standard, described as the 'heightened standard'. The House of Lords found that there was not. As the above description of the American system shows, anxiety by judges about making decisions on very serious matters on the basis of the balance of probabilities had led to a departure from the common law principles of just two standards. Baroness Hale said:

70. ... Neither the seriousness of the allegation nor the seriousness of the consequences should make any difference to the standard of proof to be applied in determining the facts. The inherent probabilities are simply something to be taken into account, where relevant, in deciding where the truth lies.

72. ... there is no logical or necessary connection between seriousness and probability. Some seriously harmful behaviour, such as murder, is sufficiently rare to be inherently improbable in most circumstances. Even then there are circumstances, such as a body with its throat cut and no weapon to hand, where it is not at all improbable. Other seriously harmful behaviour, such as alcohol or drug abuse, is regrettably all too common and not at all improbable. Nor are serious allegations made in a vacuum. Consider the famous example of the animal seen in Regent’s Park. If it is seen outside the zoo on a stretch of greensward regularly used for walking dogs, then of course it is more likely to be a dog than a lion. If it is seen in the zoo next to the lions’ enclosure when the door is open, then it may well be more likely to be a lion than a dog.

The task for the tribunal then when faced with serious allegations is to recognize that their seriousness generally means they are inherently unlikely, such that to be satisfied that a fact is more likely than not the evidence must be of a good quality. But the standard of proof remains 'the balance of probabilities'.

Other standards for presenting cases or defenses

Air of reality

See also: R v Cinous

The "air of reality" is a standard of proof used in Canada to determine whether a criminal defense may be used. The test asks whether a defense can be successful if it is assumed that all the claimed facts are to be true. In most cases, the burden of proof rests solely on the prosecution, negating the need for a defense of this kind. However, when exceptions arise and the burden of proof has been shifted to the defendant, they are required to establish a defense that bears an "air of reality." Two instances in which such a case might arise are, first, when a prima facie case has been made against the defendant or, second, when the defense mounts an affirmative defense, such as the insanity defense. This is similar to the concept of Summary judgment in the United States, though not identical.

Evidentiary standards of proof

Depending on the legal venue or intra-case hearing, varying levels of reliability of proof are considered dispositive of the inquiry being entertained. If the subject threshold level of reliability has been met by the presentation of the evidence, then the thing is considered legally proved for that trial, hearing or inquest. For example, in California, several evidentiary presumptions are codified, including a presumption that the owner of legal title is the beneficial owner (rebuttable only by clear and convincing evidence).

Examples

Criminal law

Criminal cases usually place the burden of proof on the prosecutor (expressed in the Latin brocard ei incumbit probatio qui dicit, non qui negat, "the burden of proof rests on who asserts, not on who denies"). This principle is known as the presumption of innocence, and is summed up with "innocent until proven guilty", but is not upheld in all legal systems or jurisdictions. Where it is upheld, the accused will be found not guilty if this burden of proof is not sufficiently shown by the prosecution. The presumption of innocence means three things:

• With respect to the critical facts of a case the defendant has no burden of proof whatsoever.
• The state must prove the critical facts of the case to the appropriate level of certainty.
• The jury is not to draw any inferences adverse to the defendant from the fact that he has been charged with a crime and is present in court facing the charges against him.

For example, if the defendant (D) is charged with murder, the prosecutor (P) bears the burden of proof to show the jury that D did indeed murder someone.

• Burden of proof: P
  • Burden of production: P has to show some evidence that D had committed murder. The United States Supreme Court has ruled that the Constitution requires enough evidence to justify a rational trier of fact to find guilt beyond a reasonable doubt. If the judge rules that such burden has been met, then it is up to the jury itself to decide if they are, in fact, convinced of guilty beyond a reasonable doubt. If the judge finds there is not enough evidence under the standard, the case must be dismissed (or a subsequent guilty verdict must be vacated and the charges dismissed).
    • e.g. witness, forensic evidence, autopsy report
    • Failure to meet the burden: the issue will be decided as a matter of law. In this case, D is presumed innocent
  • Burden of persuasion: if at the close of evidence, the jury cannot decide if P has established with relevant level of certainty that D had committed murder, the jury must find D not guilty of the crime of murder
    • Measure of proof: P has to prove every element of the offense beyond a reasonable doubt, but not necessarily prove every single fact beyond a reasonable doubt.

However, in England and Wales, the Magistrates' Courts Act 1980, s.101 stipulates that where a defendant relies on some "exception, exemption, proviso, excuse or qualification" in his defence in a summary trial, the legal burden of proof as to that exception falls on the defendant, though only on the balance of probabilities. For example, a person charged with being drunk in charge of a motor vehicle can raise the defense that there was no likelihood of his driving while drunk. The prosecution has the legal burden of proof beyond reasonable doubt that the defendant exceeded the legal limit of alcohol and was in control of a motor vehicle. Possession of the keys is usually sufficient to prove control, even if the defendant is not in the vehicle and is perhaps in a nearby bar. That being proved, the defendant has the legal burden of proof on the balance of probabilities that he was not likely to drive.

In 2002, such practice in England and Wales was challenged as contrary to the European Convention on Human Rights (ECHR), art.6(2) guaranteeing right to a fair trial. The House of Lords held that:

• A mere evidential burden did not contravene art. 6(2);
• A legal / persuasive burden did not necessarily contravene art. 6(2) so long as confined within reasonable limits, considering the questions:
  • What must the prosecution prove to transfer burden to the defendant?
  • Is the defendant required to prove something difficult or easily within his access?
  • What threat to society is the provision designed to combat?

In some cases, there is a reverse onus on the accused. A typical example is that of a hit-and-run charge prosecuted under the Canadian Criminal Code. The defendant is presumed to have fled the scene of a crash, to avoid civil or criminal liability, if the prosecution can prove the remaining essential elements of the offense.

Civil law

In civil law cases, such as a dispute over a contract or a claim about an accidental injury, the burden of proof usually requires the plaintiff to convince the trier of fact (whether judge or jury) of the plaintiff's entitlement to the relief sought. This means that the plaintiff must prove each element of the claim, or cause of action, in order to recover.

This rule is not absolute in civil lawsuits; unlike with criminal offenses, laws may establish a different burden of proof, or the burden in an individual case may be reversed as a matter of fairness. For example, if a bank or government agency has a legal duty to keep certain records, and a lawsuit alleges that the proper records were not kept, then the plaintiff may not be required to prove a negative; instead, the respondent could be required to prove to the court that the records were kept.

Civil cases of the U.S. Supreme Court

In Keyes v. Sch. Dist. No. 1, the United States Supreme Court stated: "There are no hard-and-fast standards governing the allocation of the burden of proof in every situation. The issue, rather, 'is merely a question of policy and fairness based on experience in the different situations'." For support, the Court cited 9 John H. Wigmore, Evidence § 2486, at 275 (3d ed. 1940). In Keyes, the Supreme Court held that if "school authorities have been found to have practiced purposeful segregation in part of a school system", the burden of persuasion shifts to the school to prove that it did not engage in such discrimination in other segregated schools in the same system.

In Director, Office of Workers' Compensation Programs v. Greenwich Collieries, the Supreme Court explained that "burden of proof" is ambiguous because it has historically referred to two distinct burdens: the burden of persuasion, and the burden of production.

The Supreme Court discussed how courts should allocate the burden of proof (i.e., the burden of persuasion) in Schaffer ex rel. Schaffer v. Weast. The Supreme Court explained that if a statute is silent about the burden of persuasion, the court will "begin with the ordinary default rule that plaintiffs bear the risk of failing to prove their claims". In support of this proposition, the Court cited 2 J. Strong, McCormick on Evidence § 337, 412 (5th ed. 1999), which states:

The burdens of pleading and proof with regard to most facts have been and should be assigned to the plaintiff who generally seeks to change the present state of affairs and who therefore naturally should be expected to bear the risk of failure of proof or persuasion.

At the same time, the Supreme Court also recognized "The ordinary default rule, of course, admits of exceptions. ... For example, the burden of persuasion as to certain elements of a plaintiff's claim may be shifted to defendants, when such elements can fairly be characterized as affirmative defenses or exemptions. ... Under some circumstances this Court has even placed the burden of persuasion over an entire claim on the defendant. ... [Nonetheless,] [a]bsent some reason to believe that Congress intended otherwise, therefore, [the Supreme Court] will conclude that the burden of persuasion lies where it usually falls, upon the party seeking relief."

Probable cause

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Probable_cause 

In United States criminal law, probable cause is the standard by which police authorities have reason to obtain a warrant for the arrest of a suspected criminal or the issuing of a search warrant. There is no universally accepted definition or formulation for probable cause. One traditional definition, which comes from the U.S. Supreme Court's 1964 decision Beck v. Ohio, is when "whether at [the moment of arrest] the facts and circumstances within [an officer's] knowledge and of which they had reasonably trustworthy information [are] sufficient to warrant a prudent [person] in believing that [a suspect] had committed or was committing an offense."

It is also the standard by which grand juries issue criminal indictments. The principle behind the standard is to limit the power of authorities to perform random or abusive searches (unlawful search and seizure), and to promote lawful evidence gathering and procedural form during criminal arrest and prosecution. The standard also applies to personal or property searches.

The term comes from the Fourth Amendment of the United States Constitution:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

Probable in this case may relate to statistical probability or to a general standard of common behavior and customs. The context of the word probable here is not exclusive to community standards, and could partially derive from its use in formal mathematical statistics as some have suggested; but cf. probō, Latin etymology.

In U.S. immigration proceedings, the “reason to believe” standard has been interpreted as equivalent to probable cause.

Probable cause should not be confused with reasonable suspicion, which is the required criteria to perform a Terry stop in the United States of America. The criteria for reasonable suspicion are less strict than those for probable cause.

Definition

A common definition is "a reasonable amount of suspicion, supported by circumstances sufficiently strong to justify a prudent and cautious person's belief that certain facts are probably true". Notable in this definition is a lack of requirement for public position or public authority of the individual making the recognition, allowing for use of the term by citizens and/or the general public. One nonlegal definition of probable cause is, “(A) reasonable ground for supposing that a charge is well-founded” (Merriam-Webster, 2019).

In the context of warrants, the Oxford Companion to American Law defines probable cause as "information sufficient to warrant a prudent person's belief that the wanted individual had committed a crime (for an arrest warrant) or that evidence of a crime or contraband would be found in a search (for a search warrant)". "Probable cause" is a stronger standard of evidence than a reasonable suspicion, but weaker than what is required to secure a criminal conviction. Even hearsay can supply probable cause if it is from a reliable source or supported by other evidence, according to the Aguilar–Spinelli test.

In Brinegar v. United States, the U.S. Supreme Court defines probable cause as "where the facts and circumstances within the officers' knowledge, and of which they have reasonably trustworthy information, are sufficient in themselves to warrant a belief by a man of reasonable caution that a crime is being committed."

History and development

The first page of the Constitution of the United States

The use of probable cause in the United States and its integration in the Fourth Amendment has roots in English common law and the old saying that "a man's home is his castle". This is the idea that someone has the right to defend their "castle" or home from unwanted "attacks" or intrusion. In the 1600s, this saying started to apply legally to landowners to protect them from casual searches from government officials.

In the 1700s, the British use of the writs of assistance and general warrants, which allowed authorities to search wherever and whenever sometimes, without expiration date, in the American colonies were raised in several court cases. The first was in Massachusetts in 1761 when a customs agent submitted for a new writ of assistance and Boston merchants challenged its legality. In the case the lawyer for the merchants James Otis argued that writs of assistance violated the fundamentals of English Law and was unconstitutional. John Adams, a lawyer at the time who later wrote the Massachusetts provision on which the Fourth Amendment heavily relied, was impacted by James Otis's argument

A case against general warrants was the English case Entick v. Carrington (1765). In that case, Lord Camden the chief judge said that general warrants were not the same as specific warrants and that parliament or case law could not authorize general warrants. Along with these statements, Lord Camden also affirmed that the needs of the state were more important than the individual's rights. This upheld the ideology of the social contract while holding to idea that the government purpose was to protect the property of the people. He called for the government to seek reasonable means in order to search private property, as well as a cause.

Probationers and parolees

In early cases in the United States, the Supreme Court held that when a person is on probation, the standard required for a search to be lawful is lowered from "probable cause" to "reasonable grounds" or "reasonable suspicion". Specifically, the degree of individualized suspicion required of a search was a determination of when there is a sufficiently high probability that criminal conduct is occurring to make the intrusion on the individual's privacy interest reasonable. The Supreme Court held in United States v. Knights:

Although the Fourth Amendment ordinarily requires the degree of probability embodied in the term "probable cause," a lesser degree satisfies the Constitution when the balance of governmental and private interests makes such a standard reasonable ... When an officer has reasonable suspicion that a probationer subject to a search condition is engaged in criminal activity, there is enough likelihood that criminal conduct is occurring that an intrusion on the probationer's significantly diminished privacy interests is reasonable.

Later, in Samson v. California, the Supreme Court ruled that reasonable suspicion is not even necessary:

The California Legislature has concluded that, given the number of inmates the State paroles and its high recidivism rate, a requirement that searches be based on individualized suspicion would undermine the State's ability to effectively supervise parolees and protect the public from criminal acts by reoffenders. This conclusion makes eminent sense. Imposing a reasonable suspicion requirement, as urged by petitioner, would give parolees greater opportunity to anticipate searches and conceal criminality.

The court held that reasonableness, not individualized suspicion, is the touchstone of the Fourth Amendment. It has been proposed that Fourth Amendment rights be extended to probationers and parolees, but such proposals have not gained traction. There is not much that remains of the Fourth Amendment rights of probationers after waiving their right to be free from unreasonable searches and seizures. An essay called "They Released Me from My Cage...But They Still Keep Me Handcuffed" was written in response to the Samson decision.

It has been argued that the requirement that a police officer must have individualized suspicion before searching a parolee's person and home was long considered a foundational element of the Court's analysis of Fourth Amendment questions and that abandoning it in the name of crime prevention represents an unprecedented blow to individual liberties.

Use of trained drug dogs

Officer training a drug dog

In the United States, use of a trained dog to smell for narcotics has been ruled in several court cases as sufficient probable cause. A K-9 Sniff in a public area is not a search according to the Supreme Court's ruling in 1983 United States v. Place. In this particular case, Place was in the New York Airport, and DEA agents took his luggage, even though he refused to have his bag searched. His luggage smelled of drugs, and the trained dog alerted the agents to this. Dogs alerting their officers provides enough probable cause for the officer to obtain a warrant. The DEA then procured a warrant and found a sizable amount of drugs in Place's luggage. It was not considered a search until after the warrant because a trained dog can sniff out the smell of narcotics, without having to open and look through the luggage. However, In Florida v. Jardines the court ruled that a police officer and narcotic-sniffing dog entering the porch of a home constitutes a search which invokes the requirement of probable cause or a valid search warrant

The power of probable cause by K-9 units smelling for drugs is not limited to just airports, but even in schools, public parking lots, high crime neighborhood streets, mail, visitors in prisons, traffic stops, etc. If there is an incident where the dog alerts its officer, the probable cause from the dog is considered enough to conduct a search, as long as one of the exceptions to a warrant are present, such as plain view, incident to arrest, automobile, exigency, or with a stop and frisk. During a traffic stop and checkpoint, it is legal for police to allow a drug dog to sniff the exterior of the car. This is legal as long as it does not cause the traffic stop to be any longer than it would have been without the dog. If the dog finds a scent, it is again a substitute for probable cause.

Cyber surveillance

Under the 2001 USA Patriot Act, law enforcement officials did not need probable cause to access communications records, credit cards, bank numbers and stored emails held by third parties. They only need reasonable suspicion that the information they were accessing was part of criminal activities. Under this, officers were authorized for a court order to access the communication information. Only certain information could be accessed under this act (such as names, addresses, and phone numbers, etc.). Probable cause was, and is, needed for more detailed information because law enforcement needs a warrant to access additional information. Generally, law enforcement was not required to notify the suspect. However, the text of the Patriot Act limits the application of that statute to issues that clearly involve the national security of the United States. The U.S. patriot Act expired on June 1, 2015.^[21]

Consent to search

Main article: Consent search

If voluntary consent is given and the individual giving the consent has authority over the search area, such as a car, house, business, etc. then a law enforcement officer does not need probable cause or even reasonable suspicion. If the person does not give voluntary consent, then the officer needs probable cause, and in some cases, a search warrant may be required to search the premises. Unless another exclusion to the fourth amendment of the US constitution occurs, when the person withdraws their consent for searching, the officer has to stop looking immediately.

Accident investigation

In the United States, the term probable cause is used in accident investigation to describe the conclusions reached by the investigating body as to the factor or factors which caused the accident. This is primarily seen in reports on aircraft accidents, but the term is used for the conclusion of diverse types of transportation accidents investigated in the United States by the National Transportation Safety Board or its predecessor, the Civil Aeronautics Board.

Related cases

In the United States

• The Supreme Court decision Illinois v. Gates lowered the threshold of probable cause by ruling that a "substantial chance" or "fair probability" of criminal activity could establish probable cause. A better-than-even chance is not required.
• The decision in Terry v. Ohio, established that "stop and frisks" (seizures) may be made under reasonable suspicion if the officer believes a crime has been committed, is, or soon will be committed with a weapon concealed on such person.
• In United States v. Matlock, the Court announced the "co-occupant consent rule" which permitted one resident to consent in the co-occupant's absence. The case established that an officer who made a search with a reasonable belief that the search was consented to by a resident did not have to provide a probable cause for the search.

However, in Georgia v. Randolph, the Supreme Court ruled, thus replacing Matlock, when officers are presented with a situation wherein two parties, each having authority to grant consent to search premises they share, but one objects over the other's consent, the officers must adhere to the wishes of the non-consenting party.

• New Jersey v. T. L. O., set a special precedent for searches of students at school. The Court ruled that school officials act as state officers when conducting searches, and do not require probable cause to search students' belongings, only reasonable suspicion. However, In Safford Unified School District v. Redding The court ruled that strip searches of students required probable cause or a search warrant.
• In O'Connor v. Ortega, the Court relied on T.L.O. to extend the reasonable suspicion standard to administrative searches of public employees' belongings or workplaces when conducted by supervisors seeking evidence of violations of workplace rules rather than criminal offenses.

Probable cause hearings

See also: Evidentiary hearing

In the various states, a probable cause hearing is the preliminary hearing typically taking place before arraignment and before a serious crime goes to trial. The judge is presented with the basis of the prosecution's case, and the defendant is afforded full right of cross-examination and the right to be represented by legal counsel. If the prosecution cannot make a case of probable cause, the court must dismiss the case against the accused.

Comparison with other countries

Sweden

In the criminal code of some European countries, notably Sweden, probable cause is a higher level of suspicion than "justifiable grounds" in a two level system of formal suspicion. The latter refers only to the suspect being able to and sometimes having a motive to commit the crime and in some cases witness accounts, whereas probable cause generally requires a higher degree of physical evidence and allows for longer periods of detention before trial. See häktning.

United Kingdom

England and Wales

Powers of arrest without a warrant can be exercised by a constable who 'has reasonable grounds' to suspect that an individual is "about to commit an offence", or is "committing an offence"; in accordance with the Serious Organised Crime and Police Act 2005 and the partially repealed Police and Criminal Evidence Act 1984. The concept of "reasonable grounds for suspecting" is used throughout the law dealing with police powers.

Scotland

In Scotland, the legal language that provides the police with powers pertaining to stopping, arresting and searching a person – who "has committed or is committing an offence", or is in possession of an offensive article, or an article used in connection with an offence – is similar to that England and Wales. The powers are provided by the Criminal Procedure (Scotland) Act 1995 and the Police, Public Order and Criminal Justice (Scotland) Act 2005.

Reasonable doubt

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Reasonable_doubt

Beyond (a) reasonable doubt is a legal standard of proof required to validate a criminal conviction in most adversarial legal systems. It is a higher standard of proof than the standard of balance of probabilities (US English: preponderance of the evidence) commonly used in civil cases because the stakes are much higher in a criminal case: a person found guilty can be deprived of liberty, or in extreme cases, life, as well as suffering the collateral consequences and social stigma attached to a conviction. The prosecution is tasked with providing evidence that establishes guilt beyond a reasonable doubt in order to get a conviction; failure to do so entitles the accused to an acquittal. This standard of proof is widely accepted in many criminal justice systems, and its origin can be traced to Blackstone's ratio, "It is better that ten guilty persons escape than that one innocent suffer."

In practice

Because a defendant is presumed to be innocent, the prosecution has the burden of proving the defendant's guilt on every element of each criminal charge beyond a reasonable doubt. To do so, the prosecution must present compelling evidence that leaves little real doubt in the mind of the trier of fact (the judge or jury) that the defendant is almost certainly guilty. For any reasonable doubt to exist, it must come from insufficient evidence, or conflicts within the evidence, that would leave an impartial factfinder less than fully convinced of the defendant's guilt. Accordingly, the standard of proof forces the factfinder to ignore unreasonable doubts—doubts that are frivolous, hypothetical, or not logically linked to the evidence—and to consider evidence favoring the accused, since reasonable doubt entitles them to an acquittal.

The term "reasonable doubt" can be criticised for having a circular definition. Therefore, jurisdictions using this standard often rely on additional or supplemental measures, such as a judge's specific instructions to a jury, to simplify or qualify reasonable doubt. Legal systems have tended to avoid quantifying the reasonable doubt standard (for example, "over 90% probability"); legal scholars from a variety of analytical perspectives have argued in favor of quantification of the criminal standard of proof.

By jurisdiction

Medieval Roman law, followed by the English jurist Edward Coke, expressed a similar idea by requiring "proofs clearer than light" for criminal conviction. The formulation "beyond reasonable doubt" is characteristic of Anglophone legal systems since the eighteenth century.

United Kingdom

England and Wales

In English common law prior to the reasonable doubt standard, passing judgment in criminal trials had severe religious repercussions for jurors. According to judicial law prior to the 1780s, "the Juryman who finds any other person guilty, is liable to the Vengeance of God upon his Family and Trade, Body and Soul, in this world and that to come." It was also believed that "[i]n every case of doubt, where one's salvation is in peril, one must always take the safer way. ... A judge who is in doubt must refuse to judge." It was in reaction to these religious fears that "reasonable doubt" was introduced in the late 18th century to English common law, thereby allowing jurors to more easily convict. Therefore, the original use of the "reasonable doubt" standard was opposite to its modern use of limiting a juror's ability to convict.

Juries in criminal courts in England and Wales are no longer customarily directed to consider whether there is reasonable doubt regarding a defendant's guilt. A 2008 conviction was appealed after the judge had said to the jury, "You must be satisfied of guilt beyond all reasonable doubt." The conviction was upheld; but the Appeal Court made clear their unhappiness with the judge's remark, indicating that the judge should instead have said to the jury simply that before they can return a verdict of guilty, they "must be sure that the defendant is guilty".

The principle of "beyond reasonable doubt" was expounded in Woolmington v DPP [1935] UKHL 1:

Juries are always told that, if conviction there is to be, the prosecution must prove the case beyond reasonable doubt. This statement cannot mean that in order to be acquitted the prisoner must "satisfy" the jury. This is the law as laid down in the Court of Criminal Appeal in Rex v. Davies 29 Times LR 350; 8 Cr App R 211, the headnote of which correctly states that where intent is an ingredient of a crime there is no onus on the defendant to prove that the act alleged was accidental. Throughout the web of the English Criminal Law one golden thread is always to be seen, that it is the duty of the prosecution to prove the prisoner's guilt subject to what I have already said as to the defence of insanity and subject also to any statutory exception. If, at the end of and on the whole of the case, there is a reasonable doubt, created by the evidence given by either the prosecution or the prisoner, as to whether the prisoner killed the deceased with a malicious intention, the prosecution has not made out the case and the prisoner is entitled to an acquittal. No matter what the charge or where the trial, the principle that the prosecution must prove the guilt of the prisoner is part of the common law of England and no attempt to whittle it down can be entertained.

Canada

In Canada, the expression "beyond a reasonable doubt" requires clarification for the benefit of the jury. The leading decision is R. v. Lifchus, where the Supreme Court discussed the proper elements of a charge to the jury on the concept of "reasonable doubt" and noted that "[t]he correct explanation of the requisite burden of proof is essential to ensure a fair criminal trial." While the Court did not prescribe any specific wording that a trial judge must use to explain the concept, it recommended certain elements that should be included in a jury charge, as well as pointing out comments that should be avoided.

The Supreme Court suggested that the concept of proof beyond a reasonable doubt should be explained to juries as follows:

• The standard of proof beyond a reasonable doubt is inextricably intertwined with that principle fundamental to all criminal trials, the presumption of innocence.
• The burden of proof rests on the prosecution throughout the trial and never shifts to the accused.
• A reasonable doubt is not a doubt based upon sympathy or prejudice and, instead, is based on reason and common sense.
• Reasonable doubt is logically connected to the evidence or absence of evidence.
• Proof beyond a reasonable doubt does not involve proof to an absolute certainty. It is not proof beyond any doubt, nor is it an imaginary or frivolous doubt.
• More is required than proof that the accused is probably guilty. A jury that concludes only that the accused is probably guilty must acquit.

The Court also warned trial judges that they should avoid explaining the concept in the following ways:

• By describing the term reasonable doubt as an ordinary expression that has no special meaning in the criminal law context.
• By inviting jurors to apply to the task before them the same standard of proof that they apply to important, or even the most important, decisions in their own lives.
• By equating proof "beyond a reasonable doubt" to proof "to a moral certainty".
• By qualifying the word "doubt" with adjectives other than reasonable, such as serious, substantial, or haunting, which may mislead the jury.
• By instructing jurors that they may convict if they are "sure" that the accused is guilty, before providing them with a proper definition as to the meaning of the words beyond a reasonable doubt.

The Supreme Court of Canada has since emphasized in R. v. Starr that an effective way to explain the concept is to tell the jury that proof beyond a reasonable doubt "falls much closer to absolute certainty than to proof on a balance of probabilities." It is not enough to believe that the accused is probably guilty, or likely guilty. Proof of probable guilt, or likely guilt, is not proof beyond a reasonable doubt.

New Zealand

In New Zealand, jurors are typically told throughout a trial that the offence must be proved "beyond reasonable doubt", and judges usually include this in the summing-up. There is no absolute prescription as to how judges should explain reasonable doubt to juries. Judges usually tell jurors that they will be satisfied beyond reasonable doubt if they "feel sure" or "are sure" that the defendant is guilty. In line with appellate court direction, judges do little to elaborate on this or to explain what it means.

Research published in 1999 found that many jurors were uncertain what "beyond reasonable doubt" meant. "They generally thought in terms of percentages, and debated and disagreed with each other about the percentage certainty required for 'beyond reasonable doubt', variously interpreting it as 100 per cent, 95 per cent, 75 per cent and even 50 per cent. Occasionally this produced profound misunderstandings about the standard of proof."

In R v Wanhalla, President Young of the Court of Appeal set out a model jury direction on the standard of proof required for a criminal conviction.

United States

The cornerstone to American criminal jurisprudence is that the accused is presumed innocent until guilt is proved beyond a reasonable doubt. The US Supreme Court held that "the Due Process clause protects the accused against conviction except upon proof beyond a reasonable doubt of every fact necessary to constitute the crime charged." The US Supreme Court first discussed the term in Miles v. United States: "The evidence upon which a jury is justified in returning a verdict of guilty must be sufficient to produce a conviction of guilt, to the exclusion of all reasonable doubt." The U.S. Supreme Court extended the reasonable doubt standard to juvenile delinquency proceedings because they are considered quasi-criminal. "[W]e explicitly hold that the Due Process Clause protects the accused against conviction except upon proof beyond a reasonable doubt of every fact necessary to constitute the crime with which he is charged."

Juries must be instructed to apply the reasonable doubt standard when determining the guilt or innocence of a criminal defendant. However, courts have struggled to define what constitutes a reasonable doubt. There is disagreement as to whether the jury should be given a definition of "reasonable doubt." Some state courts have prohibited providing juries with a definition altogether. In Victor v. Nebraska (1994), the US Supreme Court expressed disapproval of the unclear reasonable doubt instructions at issue, but stopped short of setting forth an exemplary jury instruction. Reasonable doubt came into existence in English common law and was intended to protect the jurors from committing a potentially mortal sin, since only God may pass judgment on man. The idea was to ease a juror's concern about damnation for passing judgment upon a fellow man. Since there is no formal jury instruction that adequately defines reasonable doubt, and based on the origins of the doctrine and its evolution, reasonable doubt may be resolved by determining whether there exists an alternative explanation to the facts seems plausible. If yes, then there is reasonable doubt and the accused must be acquitted.

Japan

Since 1945, Japan has also operated by a "reasonable doubt" standard, including the doctrine of in dubio pro reo, which was instituted by the Supreme Court during a controversial murder trial in 1975 (the Shiratori case brought before the Supreme Court of Japan, see for example notes on Shigemitsu Dandō). However, this is not considered an essential standard in Japan and lower level judges sometimes disregard it.

Reasonable person

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Reasonable_person 

In law, a reasonable person, reasonable man, or the man on the Clapham omnibus, is a hypothetical person of legal fiction crafted by the courts and communicated through case law and jury instructions.

Strictly according to the fiction, it is misconceived for a party to seek evidence from actual people to establish how the reasonable man would have acted or what he would have foreseen. This person's character and care conduct under any common set of facts, is decided through reasoning of good practice or policy—or "learned" permitting there is a compelling consensus of public opinion—by high courts.

In some practices, for circumstances arising from an uncommon set of facts, this person is seen to represent a composite of a relevant community's judgement as to how a typical member of said community should behave in situations that might pose a threat of harm (through action or inaction) to the public. However, cases resulting in judgment notwithstanding verdict can be examples where a vetted jury's composite judgment was deemed beyond that of the reasonable person, and thus overruled.

The reasonable person belongs to a family of hypothetical figures in law including: the "right-thinking member of society", the "officious bystander", the "reasonable parent", the "reasonable landlord", the "fair-minded and informed observer", the "person having ordinary skill in the art" in patent law, and stretching back to Roman jurists, the figure of the bonus pater familias, all used to define legal standards. While there is a loose consensus in black letter law, there is no accepted technical definition. As with legal fiction in general, it is somewhat susceptible to ad hoc manipulation or transformation, and hence the "reasonable person" is an emergent concept of common law. The "reasonable person" is used as a tool to standardize, teach law students, or explain the law to a jury.

As a legal fiction, the "reasonable person" is not an average person or a typical person, leading to great difficulties in applying the concept in some criminal cases, especially in regard to the partial defence of provocation. The standard also holds that each person owes a duty to behave as a reasonable person would under the same or similar circumstances. While the specific circumstances of each case will require varying kinds of conduct and degrees of care, the reasonable person standard undergoes no variation itself. The "reasonable person" construct can be found applied in many areas of the law. The standard performs a crucial role in determining negligence in both criminal law—that is, criminal negligence—and tort law.

The standard is also used in contract law, to determine contractual intent, or (when there is a duty of care) whether there has been a breach of the standard of care. The intent of a party can be determined by examining the understanding of a reasonable person, after consideration is given to all relevant circumstances of the case including the negotiations, any practices the parties have established between themselves, usages and any subsequent conduct of the parties.

The standard does not exist independently of other circumstances within a case that could affect an individual's judgement.

History

The "reasonable man" appeared in Richard Hooker's defence of conservatism in religion, the Laws of Ecclesiastical Polity (1594-7), where he preferred Papists to Turks and accepted the opinions of religious experts when there was no reason to dissent.

In 1835, Adolphe Quetelet detailed the characteristics of l'homme moyen (French, "average man"). His work is translated into English several ways. As a result, some authors pick "average man", "common man", "reasonable man", or stick to the original "l'homme moyen". Quetelet was a Belgian astronomer, mathematician, statistician and sociologist. He documented the physical characteristics of man on a statistical basis and discussed man's motivations when acting in society.

Two years later, the "reasonable person" made his first appearance in the English case of Vaughan v. Menlove (1837). In Menlove, the defendant had stacked hay on his rental property in a manner prone to spontaneous ignition. After he had been repeatedly warned over the course of five weeks, the hay ignited and burned the defendant's barns and stable and then spread to the landlord's two cottages on the adjacent property. Menlove's attorney admitted his client's "misfortune of not possessing the highest order of intelligence," arguing that negligence should only be found if the jury decided Menlove had not acted with "bona fide [and] to the best of his [own] judgment."

The Menlove court disagreed, reasoning that such a standard would be too subjective, instead preferring to set an objective standard for adjudicating cases:

The care taken by a prudent man has always been the rule laid down; and as to the supposed difficulty of applying it, a jury has always been able to say, whether, taking that rule as their guide, there has been negligence on the occasion in question. Instead, therefore, of saying that the liability for negligence should be co-extensive with the judgment of each individual, which would be as variable as the length of the foot of each individual, we ought rather to adhere to the rule which requires in all cases a regard to caution such as a man of ordinary prudence would observe. That was, in substance, the criterion presented to the jury in this case and, therefore, the present rule must be discharged.

English courts upheld the standard again nearly 20 years later in Blyth v. Company Proprietors of the Birmingham Water Works, holding:

Negligence is the omission to do something which a reasonable man, guided upon those considerations which ordinarily regulate the conduct of human affairs, would do, or doing something which a prudent and reasonable man would not do.

Rationale

American jurist Oliver Wendell Holmes, Jr. explained the theory behind the reasonable person standard as stemming from the impossibility of "measuring a man's powers and limitations." Individual, personal quirks inadvertently injuring the persons or property of others are no less damaging than intentional acts. For society to function, "a certain average of conduct, a sacrifice of individual peculiarities going beyond a certain point, is necessary to the general welfare." Thus, a reasonable application of the law is sought, compatible with planning, working, or getting along with others. As such, "his neighbors accordingly require him, at his proper peril, to come up to their standard, and the courts which they establish decline to take his personal equation into account." He heralded the reasonable person as a legal fiction whose care conduct under any common set of facts, is chosen—or "learned" permitting there is a compelling consensus of public opinion—by the courts.

The reasonable person standard is by no means democratic in its scope; it is, contrary to popular conception, intentionally distinct from that of the "average person," who is not necessarily guaranteed to always be reasonable. The reasonable person will weigh all of the following factors before acting:

• the foreseeable risk of harm his actions create versus the utility of his actions;
• the extent of the risk so created;
• the likelihood such risk will actually cause harm to others;
• any alternatives of lesser risk, and the costs of those alternatives.

Taking such actions requires the reasonable person to be appropriately informed, capable, aware of the law, and fair-minded. Such a person might do something extraordinary in certain circumstances, but whatever that person does or thinks, it is always reasonable.

The reasonable person has been called an "excellent but odious character."

He is an ideal, a standard, the embodiment of all those qualities which we demand of the good citizen ... [he] invariably looks where he is going, ... is careful to examine the immediate foreground before he executes a leap or bound; ... neither stargazes nor is lost in meditation when approaching trapdoors or the margins of a dock; ... never mounts a moving [bus] and does not alight from any car while the train is in motion, ... uses nothing except in moderation, and even flogs his child in meditating only on the golden mean.

English legal scholar Percy Henry Winfield summarized much of the literature by observing that:

[H]e has not the courage of Achilles, the wisdom of Ulysses or the strength of Hercules, nor has he the prophetic vision of a clairvoyant. He will not anticipate folly in all its forms but he never puts out of consideration the teachings of experience and so will guard against negligence of others when experience shows such negligence to be common. He is a reasonable man but not a perfect citizen, nor a "paragon of circumspection. ..."

Hand Rule

Main article: Calculus of negligence

Under United States common law, a well known—though nonbinding—test for determining how a reasonable person might weigh the criteria listed above was set down in United States v. Carroll Towing Co. in 1947 by the Chief Judge of the U.S. Court of Appeals for the Second Circuit, Learned Hand. The case concerned a barge that had broken her mooring with the dock. Writing for the court, Hand said:

[T]he owner's duty, as in other similar situations, to provide against resulting injuries is a function of three variables: (1) The probability that she will break away; (2) the gravity of the resulting injury, if she does; (3) the burden of adequate precautions.

While the test offered by Hand does not encompass all the criteria available above, juries in a negligence case might well still be instructed to take the other factors into consideration in determining whether the defendant was negligent.

The Sedona Conference issued its Commentary on a Reasonable Security Test to advance the Hand Rule for a cybersecurity context. The commentary adds three important articulations to the Hand Rule; a person is reasonable if no alternative safeguard would have provided an added benefit that was greater than the added burden, the utility of the risk should be considered as a factor in the calculation (as either a cost or a benefit, depending on the situation), and both qualitative and quantitative factors may be used in the test.

Personal circumstances

The legal fiction of the reasonable person is an ideal, as nobody is perfect. Everyone has limitations, so the standard requires only that people act similarly to how "a reasonable person under the circumstances" would, as if their limitations were themselves circumstances. As such, courts require that the reasonable person be viewed as having the same limitations as the defendant.

For example, a disabled defendant is held to a standard that, by necessity, represents how a reasonable person with that same disability would act. This is no excuse for poor judgment, or trying to act beyond one's abilities. Were it so, there would be as many standards as there were defendants; and courts would spend innumerable hours, and the parties much more money, on determining that particular defendant's reasonableness, character, and intelligence.

By using the reasonable person standard, courts instead use an objective tool and avoid such subjective evaluations. The result is a standard that allows the law to behave in a uniform, foreseeable, and neutral manner when attempting to determine liability.

Children

One broad allowance made to the reasonable person standard is for children. The standard here requires that a child act in a similar manner to how a "reasonable person of like age, intelligence, and experience under like circumstances" would act. In many common law systems, children under the age of 6 or 7 are typically exempt from any liability, whether civil or criminal, as they are deemed to be unable to understand the risk involved in their actions. This is called the defense of infancy: in Latin, doli incapax. In some jurisdictions, one of the exceptions to these allowances concern children engaged in what is primarily considered to be high-risk adult activity, such as operating a motor vehicle, and in some jurisdictions, children can also be "tried as an adult" for serious crimes, such as murder, which causes the court to disregard the defendant's age.

Mentally ill

The reasonable person standard makes no allowance for the mentally ill. Such a refusal goes back to the standard set in Menlove, where Menlove's attorney argued for the subjective standard. In the 170 years since, the law has kept to the legal judgment of having only the single, objective standard. Such judicial adherence sends a message that the mentally ill would do better to refrain from taking risk-creating actions, unless they exercise a heightened degree of self-restraint and precaution, if they intend to avoid liability.

Generally, the courts have reasoned that by not accepting mental illness as a bar to recovery, a potentially liable third party, such as a caregiver, will be more likely to protect the public. The courts have also stated the reason that members of the public are unable to identify a mentally ill person, as they can a child or someone with a physical disability.

Professionals

When a person attempts a skilful act, the "reasonable person under the circumstances" test is elevated to a standard of whether the person acted how a "reasonable professional under the circumstances" would have, whether or not that person is actually a professional, has training, or has experience. Other factors also become relevant, such as the degree to which a professional is educated (i.e., whether a specialist within the specific field, or just a general practitioner of the trade), and customary practices and general procedures of similar professionals. However, such other relevant factors are never dispositive.

Some professions may maintain a custom or practice long after a better method has become available. The new practices, though less risky, may be entirely ignored. In such cases, the practitioner may very well have acted unreasonably despite following custom or general practices.

Medical professionals

In healthcare, plaintiffs must prove via expert testimony the standard of medical care owed and a departure from that standard. The only exception to the requirement of expert testimony is where the departure from accepted medical practices was so egregious that a layperson can readily recognize the departure.

However, controversial medical practices can be deemed reasonable when followed by a respected and reputable minority of the medical field, or where the medical profession cannot agree over which practices are best.

Armed professionals

The "reasonable officer" standard is a method often applied to law enforcement and other armed professions to help determine if a use of force was excessive. The test is whether an appropriately trained professional, knowing what the officer knew at the time and following guidelines (such as a force continuum), would have used the same level of force or higher. If the level of force is justified, the quantity of force is usually presumed to have been necessary unless there are other factors. For example, if a trained police officer was justified in fatally shooting a suspect, the number of shots is presumed to have been necessary barring other factors, such as a reckless disregard of others' safety or that additional force was used when the suspect was no longer a threat.

Inexperience

When anyone undertakes a skilful task that creates a risk to others, that person is held to the minimum standard of how a reasonable person experienced in that task would act, regardless of their actual level of experience.

External circumstances

Factors beyond the defendant's control are always relevant. Additionally, so is the context within which each action is made. Many things affect how a person acts: individual perceptions, knowledge, the weather, etc. The standard of care required depends on the circumstances, but is always that which is reasonable.

While community customs may be relied upon to indicate what kind of action is expected in the circumstances, these are not themselves conclusive of what a reasonable person would do.

It is precisely for this wide-ranging variety of possible facts that the reasonable person standard is so broad (and often confusing and difficult to apply). However, a few general areas of relevant circumstances rise above the others.

Emergency doctrine

Allowing for circumstances under which a person must act urgently is important to prevent hindsight bias by the trier of fact. A reasonable person may not always act as they would when more relaxed. It is fair that actions be judged in light of any exigent conditions that could have affected how the defendant acted.

Available resources

People must make do with what they have or can get. Such circumstances are relevant to any determination of whether the defendant acted reasonably. Where resources are scarce, some actions may be reasonable that would not be were there plenty.

Negligence per se

Main article: Negligence per se

Because a reasonable person is objectively presumed to know the law, noncompliance with a local safety statute may also constitute negligence. The related doctrine of negligence per se addresses the circumstances under which the law of negligence can become an implied cause of action for breaching a statutory standard of care. Conversely, minimal compliance with a safety statute does not always absolve a defendant if the trier of fact determines that a reasonable person would have taken actions beyond and in excess of what the statute requires. The trier of fact can deem the defendant's duty of care met by finding that the statute's standard itself is reasonable and the defendant acted in accordance with what it statute contemplated.

Reasonable bystander

Main article: Offer and acceptance

For common law contracts, disputes over contract formation are subjected to what is known as the objective test of assent in order to determine whether a contract exists. This standard is also known as the officious bystander, reasonable bystander, reasonable third party, or reasonable person in the position of the party. This is in contrast to the subjective test employed in most civil law jurisdictions. The test stems from attempts to balance the competing interests of the judicial policies of assent and of reliability. The former holds that no person ought to be contractually obligated if they did not consent to such an agreement; the latter holds that if no person can rely on actions or words demonstrating consent, then the whole system of commercial exchange will ultimately collapse.

Prior to the 19th century, courts used a test of subjective evaluation; that is, the trier of fact determined each party's understanding. If both parties were of the same mind and understanding on matters, then assent was manifested and the contract was valid. Between the 19th and 20th centuries, the courts shifted toward the objectivist test, reasoning that subjective testimony was often unreliable and self-serving.

From those opposite principles, modern law has found its way to a rough middle ground, though it still shows a strong bias toward the objective test. Promises and agreements are reached through manifestations of consent, and parties are liable for actions that deliberately manifest such consent; however, evidence of either party's state of mind can be used to determine the context of the manifestation if said evidence is reliable and compatible with the manifestation in question, though such evidence is typically given very little weight.

Another circumstance where the reasonable bystander test is used occurs when one party has inadvertently misstated the terms of the contract, and the other party sues to enforce those terms: if it would have been clear to a reasonable bystander that a mistake had been made, then the contract is voidable by the party who made the error; otherwise, the contract is binding.

Reasonable person standard for victims

Reasonable woman

"Reasonable woman" redirects here. For the Sia album, see Sia discography.

Sexual harassment

A variant of the reasonable person can be found in sexual harassment law as the reasonable woman standard. The variation recognizes a difference between men and women regarding the effect of unwanted interaction with a sexual tone. As women have historically been more vulnerable to rape and sex-related violence than have men, some courts believe that the proper perspective for evaluating a claim of sexual harassment is that of the reasonable woman. Notably, J. Scalia held that women did not have constitutional protection from discrimination under the fourteenth amendment equal protection clause, where by extension of logic, held the "reasonable woman" standard to be of moot value. However, such has not been the majority opinion of the court.

Satire

Though the use of the reasonable woman standard has gained traction in some areas of the law, the standard has not escaped the crosshairs of humorists. In 1924, legal humorist A. P. Herbert considered the concept of the reasonable man at length in the fictional case of "Fardell v. Potts." In Herbert's fictional account, the judge addressed the lack of a reasonable woman standard in the common law, and ultimately concluded that "a reasonable woman does not exist."

L'homme moyen sensuel

The concept of l'homme moyen sensuel does not speak of a reasonable person's ability, actions, or understandings. Rather it refers to the response of a reasonable person when presented with some form of information either by image or sound, or upon reading a book or magazine. A well-known application of the concept is Judge John M. Woolsey's lifting of the ban on the book Ulysses by James Joyce. That ruling contemplated the effect the book would have upon a reasonable person of reasonable sensibility. Similarly, when the publisher of Howl and Other Poems was charged in California with publishing an obscene book, the concept of l'homme moyen sensuel influenced the court's finding of innocence. It was nearly two decades after Woolsey that the US Supreme Court set down the standard by which materials, when viewed by l'homme moyen sensuel, were judged either obscene or not. Generally, it has been l'homme moyen sensuel that has dictated what is and is not obscene or pornographic in books, movies, pictures, and now the Internet for at least the past 100 years.

Qualifications

Very often, for instance, in the case of noise ordinances, the enforcement of the law is only for the purpose of protecting the right of a "reasonable person of normal sensitivity".