Is a defendant's prior criminal conviction for possession of a firearm admissible to prove knowledge of the crime?

As defendant was charged with felon in possession of a firearm, his status as a previously convicted felon was clearly relevant. If "defendant will stipulate to ex-felon [sic] status, evidence of the nature of his prior convictions still may and should be withheld from the jury, since such evidence is irrelevant to the ex-felon [sic] issue." (People v. Valentine (1986) 42 Cal.3d 170, 173.) However, this rule does not prohibit the nature of the conviction from being disclosed if relevant to some other issue in the case. (People v. Karis (1988) 46 Cal.3d 612, 639, fn. 18.)

"While evidence of other crimes is inadmissible when offered to prove criminal disposition or the propensity of the accused to commit a particular crime [citation], such evidence is admissible when offered to prove such issues as motive, opportunity, intent, common design and plan, knowledge or identity. (Evid. Code, 1101, subd. (b) . . . .)" (People v. Perez (1974) 42 Cal.App.3d 760, 763-764.) "An essential element of the crime of possession of narcotics is knowledge of the narcotic character of the article possessed [citation] and evidence of prior use of narcotics . . . is admissible for such purpose." (People v. Hancock (1957) 156 Cal.App.2d 305, 312; see also People v. Pijal (1973) 33 Cal.App.3d 682, 691 [prior narcotics conviction admissible to prove knowledge].)