PROBABLE CAUSE; PROBABLE CAUSE IS A REQUIREMENT FOUND IN THE FOURTH AMENDMENT THAT MUST USUALLY BE MET BEFORE POLICE MAKE AN ARREST, CONDUCT A SEARCH, OR RECEIVE A WARRANT. COURTS USUALLY FIND PROBABLE CAUSE WHEN THERE IS A REASONABLE BASIS FOR BELIEVING THAT A CRIME MAY HAVE BEEN COMMITTED (FOR AN ARREST) OR WHEN EVIDENCE OF THE CRIME IS PRESENT IN THE PLACE TO BE SEARCHED (FOR A SEARCH).