What is the test to sustain a conviction for possession with intent to distribute?

To sustain a conviction for possession with intent to distribute, the Government must prove that Vigoa had dominion and control of the cocaine, and knowledge of its existence. United States v. Castillo, 866 F.2d 1071, 1086 (9th Cir.1988). Dominion and control may be demonstrated by physical custody or constructive possession. See United States v. Batimana, 623 F.2d 1366, 1369 (9th Cir.), cert. denied, 449 U.S. 1038 (1980). A person has constructive possession of an object if he has sufficient dominion and control to give him the power of disposal. Id.