California Code, Penal Code - PEN § 25850

(1) Where the person previously has been convicted of any felony, or of any crime made punishable by a provision listed in Section 16580, as a felony.

(2) Where the firearm is stolen and the person knew or had reasonable cause to believe that it was stolen, as a felony.

(3) Where the person is an active participant in a criminal street gang, as defined in subdivision (a) of Section 186.22, under the Street Terrorism Enforcement and Prevention Act (Chapter 11 (commencing with Section 186.20) of Title 7 of Part 1), as a felony.

(4) Where the person is not in lawful possession of the firearm, or is within a class of persons prohibited from possessing or acquiring a firearm pursuant to Chapter 2 (commencing with Section 29800) or Chapter 3 (commencing with Section 29900) of Division 9 of this title, or Section 8100 or 8103 of the Welfare and Institutions Code, as a felony.

(5) Where the person has been convicted of a crime against a person or property, or of a narcotics or dangerous drug violation, by imprisonment pursuant to subdivision (h) of Section 1170, or by imprisonment in a county jail not to exceed one year, by a fine not to exceed one thousand dollars ($1,000), or by both that imprisonment and fine.

(6) Where the person is not listed with the Department of Justice pursuant to Section 11106 as the registered owner of the handgun, by imprisonment pursuant to subdivision (h) of Section 1170, or by imprisonment in a county jail not to exceed one year, or by a fine not to exceed one thousand dollars ($1,000), or both that fine and imprisonment.

(7) In all cases other than those specified in paragraphs (1) to (6), inclusive, as a misdemeanor, punishable by imprisonment in a county jail not to exceed one year, by a fine not to exceed one thousand dollars ($1,000), or by both that imprisonment and fine.

(d)(1) Every person convicted under this section who has previously been convicted of an offense enumerated in Section 23515, or of any crime made punishable under a provision listed in Section 16580, shall serve a term of at least three months in a county jail, or, if granted probation or if the execution or imposition of sentence is suspended, it shall be a condition thereof that the person be imprisoned for a period of at least three months.

(2) The court shall apply the three-month minimum sentence 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 minimum imprisonment required in this section or by granting probation or suspending the imposition or execution of sentence with conditions other than those set forth in this section, 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 that disposition.

(1) When the person arrested has violated this section, although not in the officer's presence.

(2) Whenever the officer has reasonable cause to believe that the person to be arrested has violated this section, whether or not this section has, in fact, been violated.