Cal. Penal Code - PEN § 29900. Section 29900.
(a)
(1)
Notwithstanding subdivision (a) of Section 29800, any person who has been previously convicted of any of the offenses listed in Section 29905 and who owns or has in possession or under custody or control any firearm is guilty of a felony.
(2)
A dismissal of an accusatory pleading pursuant to Section 1203.4a involving an offense set forth in Section 29905 does not affect the finding of a previous conviction.
(3)
If probation is granted, or if the imposition or execution of sentence is suspended, it shall be a condition of the probation or suspension that the defendant serve at least six months in a
county jail.
(b)
(1)
Any person previously convicted of any of the offenses listed in Section 29905 which conviction results from certification by the juvenile court for prosecution as an adult in adult court under the provisions of Section 707 of the Welfare and Institutions Code, who owns or has in possession or under custody or control any firearm, is guilty of a felony.
(2)
If probation is granted, or if the imposition or execution of sentence is suspended, it shall be a condition of the probation or suspension that the defendant serve at least six months in a county jail.
(c)
The court shall apply the minimum sentence as specified in subdivisions (a) and (b) except in unusual cases where the interests of justice would best be served by granting probation or suspending the imposition or
execution of sentence without the imprisonment required by subdivisions (a) and (b), or by granting probation or suspending the imposition or execution of sentence with conditions other than those set forth in subdivisions (a) and (b), in which case the court shall specify on the record and shall enter on the minutes the circumstances indicating that the interests of justice would best be served by the disposition.