The Dropped Rock

Late one night, two plain-clothes police officers were patrolling a high-crime area of Oakland in an unmarked car when they spotted four or five youths gathered around a parked car. When the youths noticed the officers' vehicle approaching, they scattered in different directions. The Defendant and a companion ran one way down an alley, and an officer got out of the car and chased the Defendant on foot along a winding route through nearby streets. The Defendant reappeared still running, glancing back over his shoulder as the officer closed the gap behind him. Just as the officer got close, the Defendant tossed away a small rock. A moment later, the officer caught up to him, brought him to the ground, and handcuffed him. Officers then recovered the discarded rock, which tested positive as crack cocaine. What remains in dispute is whether, and at what exact point in this sequence, a seizure of the Defendant took place — before or after he threw the drugs away.