Cal. Penal Code § 11115

In any case in which a sheriff, police department or other law enforcement agency makes an arrest and transmits a report of the arrest to the Department of Justice or to the Federal Bureau of Investigation, it shall be the duty of such law enforcement agency to furnish a disposition report to such agencies whenever the arrested person is transferred to the custody of another agency or is released without having a complaint or accusation filed with a court. The disposition report in such cases shall be furnished to the appropriate agencies within 30 days of release or transfer to another agency. If either of the following dispositions is made, the disposition report shall so state: (a) “Arrested for intoxication and released,” when the arrested party is released pursuant to paragraph (2) of subdivision (b) of Section 849. (b) “Detention only,” when the detained party is released pursuant to paragraph (1) of subdivision (b) of Section 849 or issued a certificate pursuant to subdivision (b) of Section 851.6. In such cases the report shall state the specific reason for such release, indicating that there was no ground for making a criminal complaint because (1) further investigation exonerated the arrested party, (2) the complainant withdrew the complaint, (3) further investigation appeared necessary before prosecution could be initiated, (4) the ascertainable evidence was insufficient to proceed further, (5) the admissible or adducible evidence was insufficient to proceed further, or (6) other appropriate explanation for release.