California Code, Penal Code - PEN § 290.016

(a) On or after January 1, 1998, upon incarceration, placement, or commitment, or prior to release on probation, any person who is required to register under the Act shall preregister. The preregistering official shall be the admitting officer at the place of incarceration, placement, or commitment, or the probation officer if the person is to be released on probation. The preregistration shall consist of all of the following:

(b) Within three days thereafter, the preregistering official shall forward the statement, fingerprints, photograph, and vehicle license plate number, if any, to the Department of Justice.