State of Arizona, Appellee v. Johnathon Bernard Serna, Appellant

Summary

The court held that an officer may not frisk a person during an initially consensual encounter merely because the person is armed. A frisk requires reasonable suspicion both that criminal activity is afoot and that the person is armed and dangerous; because the officer lacked suspicion of criminal activity when he ordered Serna to raise his hands, the frisk violated the Fourth Amendment. The court vacated the court of appeals' opinion and reversed Serna's conviction and sentence.