In Crisman v. Commonwealth, 197 Va. 17, 87 S.E.2d 796 (1955), the Supreme Court of Virginia addressed circumstances which mirror the instant record. Police stopped a vehicle occupied by five persons, including the two defendants, the Crisman brothers, both in the back seat. A search of the car revealed heroin on the rear floor, but everyone denied knowledge of the narcotics. In reversing the conviction, the Court concluded that it would be unreasonable to assume that the occupants of the front seat would have dropped the powder in the back of the car in plain view of the defendants. It appears equally unreasonable to assume that the occupants of the rear seat would have deposited the drug immediately under their feet rather than spill it to the winds through the car window. . . . Who put it there or who had possession of it before it was placed on the floor we do not know. The conclusion that the defendants, or either of them, possessed the drug is speculation rather than proof. Id. at 20, 87 S.E.2d at 798-99.