On what is probable cause based?

Probable cause is based on the totality of the circumstances, which means that it is determined by evaluating all available information together rather than in isolation. This standard requires law enforcement to consider all facts and circumstances known at the time of the arrest or search. The totality of the circumstances approach allows for a more comprehensive assessment of whether there is a reasonable basis to believe that a crime has been committed, or that evidence of a crime can be found in the location to be searched.

This approach emphasizes the importance of context and the interplay between various factors that contribute to a law enforcement officer's belief in the likelihood of criminal activity. It recognizes that individual pieces of evidence, when viewed in combination, can create a stronger case for probable cause than when viewed separately.

Thus, the correct understanding of probable cause adheres to this holistic examination of circumstances, making it a foundational principle in determining lawful searches and seizures under the Fourth Amendment.