A car without a driver moves; a man dies. How come?
The murderer sets the car on a slope above the hot dog stand where the victim works. He then wedges an ice block in the car to keep the brake pedal down, and puts the car in neutral, after which he flies to another city to avoid suspicion. It's a warm day; when the ice melts, the car rolls down the hill and strikes the hot dog man at his roadside stand, killing him.