Knowles v. Iowa

An Iowa police officer stopped petitioner Knowles for speeding, but issued him a citation rather than arresting him. The question presented is whether such a procedure authorizes the officer, consistently with the Fourth Amendment, to conduct a foil search of the car. We answer this question "no.”

Knowles was stopped in Newton, Iowa, after having been clocked driving 43 miles per hour on a road where the speed limit was 25 miles per hour. The police officer issued a citation to Knowles, although under Iowa law he might have arrested him. The officer then conducted a foil search of the car, and…