APOST Legal Practice Exam 2026 – Comprehensive Prep Tool

Probable cause is a reasonable belief, based on the facts and circumstances known to the officer, that a crime has been or is being committed or that evidence of a crime is located at a particular place. It sits between a mere hunch and absolute certainty: it requires more than guesswork, but it does not require proof beyond a reasonable doubt. Courts evaluate probable cause using the totality of the circumstances—the officer’s observations, information from reliable sources, and any corroborating details—making an objective, not purely personal, assessment. This standard justifies arrests and warrants to search for evidence; without it, police action generally isn’t supported. The idea that it’s merely a hunch, a certainty, or a guess about guilt is too weak or inappropriate, since probable cause must be grounded in facts and evidence that would lead a reasonable person to believe a crime is or has been committed or that evidence is present at a location.