What are the elements of unlawful possession?

"The elements of unlawful possession may be established by circumstantial evidence and any reasonable inferences drawn from such evidence. [Citations.]" (People v. Williams (1971) 5 Cal.3d 211, 215.) Possession may be actual or constructive. The defendant is not required to have exclusive control over the place where the contraband was found. "Constructive possession occurs when the accused maintains control or a right to control the contraband; possession may be imputed when the contraband is found in a place which is immediately and exclusively accessible to the accused and subject to his dominion and control, or to the joint dominion and control of the accused and another. [Citation.]" (Ibid.)