California Code, Civil Code - CIV § 1714.3

Civil liability for any injury to the person or property of another proximately caused by the discharge of a firearm by a minor under the age of 18 years shall be imputed to a parent or guardian having custody and control of the minor for all purposes of civil damages, and such parent or guardian shall be jointly and severally liable with such minor for any damages resulting from such act, if such parent or guardian either permitted the minor to have the firearm or left the firearm in a place accessible to the minor.

The liability imposed by this section is in addition to any liability otherwise imposed by law. However, no person, or group of persons collectively, shall incur liability under this section in any amount exceeding thirty thousand dollars ($30,000) for injury to or death of one person as a result of any one occurrence or, subject to the limit as to one person, exceeding sixty thousand dollars ($60,000) for injury to or death of all persons as a result of any one such occurrence.