Investigative stop of a minor infraction which did not occur in the officer’s presence was a violation of Fourth Amendment.

Grigg appealed the district court’s denial of his motion to suppress an unregistered automatic weapon which officers discovered while conducting an investigative stop pursuant to a citizen’s complaint that Grigg had been playing his car stereo at an excessive volume. Police pulled over the car based on a complaining neighbor saying “that’s the car,” but at the time of the stop, the car was not playing loud music. Grigg quickly spilled that he had a hunting rifle behind the seat. The appellate court reversed the district court judge’s denial of a motion to suppress the gun and the statements, finding, that investigatory stops of cars are not constitutional if the police are investigating a misdemeanor that did not occur in their presence. “The exceedingly harmless past misdemeanor conduct: allegedly playing one’s car stereo at a volume in suspected violation of a local noise ordinance, need not spur the police into instant action as might the opportunity to stop a reputedly armed felon, street fighter, or reckless driver….Given the lack of exigency to seize Grigg temporarily, his interest in personal security against governmental intrusion is entitled to more deference…. To validate the investigative stop under these circumstances would invite the erosion of the Fourth Amendment rights of Grigg and others.”