Is a defendant required to have knowledge of the presence of a firearm as an element of constructive possession?

All Ninth Circuit case law requires that the defendant have knowledge of the presence of the contraband as an element of constructive possession. The cases also add some element that distinguishes possession from mere presence or accessibility. It is not enough that a person has the power to control the contraband, in the sense that he simply is in the presence of the contraband and could reach out and take it. Compare United States v. Behanna, 814 F.2d 1318, 1320 (9th Cir.1987) (holding that the government must do more than show that the defendant was present as a passenger in the vehicle and within reach of the weapon.).