What is the legal test for a conviction for felon in possession of a firearm under section 12021, subdivision (a) of the Penal Code?

^1. "Effective January 1, 2012, former section 12021(a), was repealed and reenacted without substantive change as section 29800, subdivision (a)." (People v. White (2014) 223 Cal.App.4th 512, 518, fn. 2 (White).) For ease of reference, we hereafter refer to a conviction for felon in possession of a firearm as a conviction under section 12021, subdivision (a). All further statutory references are to the Penal Code unless otherwise specified.

^2. The court relies in part on this court's unpublished opinion in People v. Gonsalves (March 13, 1998, D026965) for the facts of Gonsalves's current offense and portions of the procedural history.