Probable cause

In <a href="/facts/United_States_criminal_law/EwLEbI0F">United States criminal law</a>, probable cause is the legal standard by which police authorities have reason to obtain a warrant for the arrest of a suspected <a href="/facts/Criminal/BfoRzbL3">criminal</a> and for a court's issuing of a <a href="/facts/Search_warrant/Dn4yseJt">search warrant</a>. One definition of the standard derives from the U.S. Supreme Court decision in the case of <a href="/facts/Beck_v._Ohio/l2R6MQXq">Beck v. Ohio</a> (1964), that probable cause exists when “at [the moment of arrest] the facts and circumstances within [the] knowledge [of the police], 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.”
Moreover, the <a href="/facts/Grand_jury/DSqqYg2v">grand jury</a> uses the probable cause standard to determine whether or not to issue a criminal indictment. The principle behind the probable cause standard is to <a href="/facts/Limited_power/erlL7IMq">limit the power</a> of authorities to conduct <a href="/facts/Unlawful_search_and_seizure/mGQXEn5b">unlawful search and seizure</a> of person and property, and to promote formal, forensic procedures for gathering lawful evidence for the prosecution of the arrested criminal. In the case of <a href="/facts/Berger_v._New_York/P8AhfaVo">Berger v. New York</a> (1967), the Supreme Court said that the purpose of the probable-cause requirement of the <a href="/facts/Fourth_Amendment_to_the_United_States_Constitution/S1KsVyvf">Fourth Amendment</a> is to keep the state out of Constitutionally protected areas until the state has reason to believe that a specific crime is being committed or has been committed. The term of criminal law, the probable cause standard is stipulated in the text of the Fourth Amendment to the U.S. 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.
Moreover, in U.S. immigration law, the term “reason to believe” is equivalent to the probable cause standard of criminal law, and should not be confused with <a href="/facts/Reasonable_suspicion/yl6YIPNH">reasonable suspicion</a>, which is the legal criterion required to perform a <a href="/facts/Terry_stop/yMVt2XxW">Terry stop</a> in the U.S.

Probable cause open-in-new

Probable cause