Cal. Penal Code § 30360

Commencing February 1, 2011, a vendor shall not knowingly make a false entry in, fail to make a required entry in, fail to obtain the required thumbprint, or otherwise fail to maintain in the required manner, records prepared in accordance with Section 30352. If the right thumbprint is not available, then the vendor shall have the purchaser or transferee use the left thumb, or any available finger, and shall so indicate on the form.