California Code, Penal Code - PEN § 816

A warrant of arrest shall be directed generally to any peace officer, or to any public officer or employee authorized to serve process where the warrant is for a violation of a statute or ordinance which such person has the duty to enforce, in the state, and may be executed by any of those officers to whom it may be delivered.

When a warrant of arrest has been delivered to a peace officer and the person named in the warrant is otherwise lawfully in the custody of the peace officer, the warrant may be executed by the peace officer or by any clerk of a city or county jail authorized to act and acting under the peace officer's direction.