In United States criminal law, Probable cause refers to the standard by which a police officer may make an arrest or conduct a personal or property search. This term comes from the Fourth Amendment of the United States Constitution.

Definition

The most widely held common definition is "a reasonable belief that a crime has been committed". This definition has been criticised for being an example of circular reasoning, especially in the phrase "probable cause to believe that". 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 is backed up by other evidence.

Related cases

The Supreme Court decision Illinois v. Gates (1983) 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 (1968) established that some brief seizures may be made without probable cause. If an officer has a reasonable suspicion that a crime has been committed or will soon be committed, that officer may briefly detain a suspect to frisk him for weapons and question him. This is known as a "Terry stop."

The Illinois v. Rodriguez case of 1990 established that a factual error made by an officer, if it was a reasonable mistake under the circumstances, does not invalidate probable cause nor invalidate any evidence obtained.

Probable cause hearings

In the United States a probable cause hearing is the preliminary hearing that typically takes place after 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 out a case of probable cause the court must dismiss the case against the accused. See also: evidentiary hearing.

External links

• Legal information about probable cause
• The Lawful Arrest FAQ
• Further information from Flexyourrights.org