Pen. Code, § 30630

(a) Sections 30605 and 30610 shall not prohibit the possession or use of assault weapons or a .50 BMG rifle by sworn peace officer members of those agencies specified in Section 30625 for law enforcement purposes, whether on or off duty.

(b) (1) Sections 30600, 30605, and 30610 shall not prohibit the sale, delivery, or transfer of an assault weapon or a .50 BMG rifle to, or the possession of an assault weapon or a .50 BMG rifle by, a sworn peace officer member of an agency specified in Section 30625 if the peace officer is authorized by the officer’s employer to possess or receive the assault weapon or the .50 BMG rifle. Required authorization is defined as verifiable written certification from the head of the agency, identifying the recipient or possessor of the assault weapon as a peace officer and authorizing that person to receive or possess the specific assault weapon.

(2) For this exemption to apply, in the case of a peace officer who possesses or receives the assault weapon prior to January 1, 2002, the officer shall register the assault weapon on or before April 1, 2002, pursuant to former Section 12285, as it read at any time from when it was enacted by Section 3 of Chapter 19 of the Statutes of 1989, to and including when it was amended by Section 9 of Chapter 129 of the Statutes of 1999. In the case of a peace officer who possesses or receives the assault weapon on or after January 1, 2002, the officer shall, not later than 90 days after possession or receipt, register the assault weapon pursuant to Article 5 (commencing with Section 30900), or pursuant to former Section 12285, as it read at any time from when it was amended by Section 9 of Chapter 129 of the Statutes of 1999 to when it was repealed by the Deadly Weapons Recodification Act of 2010. In the case of a peace officer who possesses or receives a .50 BMG rifle on or before January 1, 2005, the officer shall register the .50 BMG rifle on or before April 30, 2006. In the case of a peace officer who possesses or receives a .50 BMG rifle after January 1, 2005, the officer shall register the .50 BMG rifle not later than one year after possession or receipt.

(3) With the registration, the peace officer shall include a copy of the authorization required pursuant to this subdivision.

(c) Nothing in this article shall be construed to limit or prohibit the sale, delivery, or transfer of an assault weapon or a .50 BMG rifle to, or the possession of an assault weapon or a .50 BMG rifle by, a member of a federal law enforcement agency provided that person is authorized by the employing agency to possess the assault weapon or .50 BMG rifle.