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.
Responsibility for criminal law and criminal justice in the United States is shared between the states and the federal government.
What is Probable Cause? by Flex Your Rights
The standard also applies to personal or property searches.
Aaron Hernandez - Probable Cause Hearing by croakerqueen123
Probable cause, in conjunction with a preponderance of the evidence, also refers to the standard by which a grand jury believes that a crime has been committed.
A grand jury is a legal body that is empowered to conduct official proceedings to investigate potential criminal conduct and to determine whether criminal charges should be brought.
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.
Probability is the measure of the likelihood that an event will occur.
The context of the word "probable" here is not exclusive to community standards and does not predate statistics, as some have suggested.