California Code, Food and Agricultural Code (Formerly Agricultural Code) - FAC § 31152

(a) The dog is found in the act of killing, wounding, or persistently pursuing livestock or poultry on land or premises not owned or possessed by the owner of the dog.

(b) The dog has no readily visible identification tag or license tag prescribed by Section 30951 and is worrying livestock or poultry on land or premises not owned or possessed by the owner of the dog. If the dog has on him any readily visible identification tag or license tag prescribed by Section 30951, and the dog is found in the act of worrying livestock or poultry on land or premises not owned or possessed by the owner of the dog, the dog may only be killed if the dog has, and the owner has been notified that the dog has, previously so worried livestock or poultry.

(c) The person has such proof as conclusively shows that the dog has been recently engaged in killing or wounding livestock or poultry on land or premises not owned or possessed by the dog's owner.

No action, civil or criminal, shall be maintained for killing a dog as authorized by this section.