California License Plate Reader Laws

Status at a glance

Source note: California’s official legislative site blocked our automated access, so the statutory text below is taken from the Attorney General’s bulletin, which quotes the statute directly, and from the California Supreme Court’s opinion.

What SB 34 requires

Senate Bill 34 took effect January 1, 2016, and is codified at Civil Code § 1798.90.5 et seq. According to the Attorney General’s 2023 guidance, it requires ALPR operators and end-users, including law enforcement agencies, to:

• maintain reasonable security procedures to protect ALPR information “from unauthorized access, destruction, use, modification, or disclosure” (§§ 1798.90.51(a), 1798.90.53(a));
• implement a usage and privacy policy, available to the public in writing and “posted conspicuously” on the agency’s website (§§ 1798.90.51(b), 1798.90.53(b)); and
• for operators that access or provide access to ALPR information, keep a record of each access, including the date and time, the plate or other data used to query, the user name and affiliated organization, and “the purpose for accessing the information” (§ 1798.90.52(a)).

A public agency that operates or plans to operate an ALPR system must also “provide an opportunity for public comment at a regularly scheduled public meeting of the governing body of the public agency before implementing the program” (§ 1798.90.55(a)).

Sharing: California public agencies only

A public agency “shall not sell, share, or transfer ALPR information, except to another public agency, and only as otherwise permitted by law” (§ 1798.90.55(b)). The Attorney General’s Bulletin 2023-DLE-06 explains that “public agency” means California state and local agencies. So the law “does not permit California LEAs to share ALPR information with private entities or out-of-state or federal agencies, including out-of-state and federal law enforcement agencies.” The bulletin says this applies to databases agencies access through vendors as well. Data hosting and towing services aren’t considered sharing. See can police search Flock data from other states?

What the State Auditor found

The State Auditor’s February 2020 report reviewed four agencies: Fresno, Los Angeles, Marin and Sacramento. It found that none had a usage and privacy policy implementing all the legal requirements. Three had shared images with hundreds of entities, Sacramento with over a thousand, without evidence of verifying each recipient’s right and need to access them. The agencies had not audited system use. The Auditor also found that 99.9 percent of the 320 million images Los Angeles stored were of vehicles not on a hotlist when photographed. These findings describe those agencies at that time, not every California agency today.

Public records: the ACLU case

In ACLU Foundation of Southern California v. Superior Court (Aug. 31, 2017), the California Supreme Court held that the Los Angeles police and sheriff’s ALPR scanning “does not produce records of investigations,” because “the scans are not conducted as part of a targeted inquiry into any particular crime or crimes.” So the investigative-records exemption of the California Public Records Act didn’t apply.

The court agreed with the trial court that the public interest in not disclosing raw ALPR scan data “clearly outweighs” the public interest in disclosure. It sent the case back to consider whether the data could reasonably be anonymized or redacted so that disclosure would be required. See public records requests for ALPR.

Retention

The State Auditor found in 2020 that retention periods “vary widely” and recommended that the Legislature set a maximum. Police1 reported that California ALPR legislation was the subject of an April 2026 hearing. We haven’t verified whether a statewide maximum has been enacted. Check the agency’s posted usage and privacy policy for its retention period.

What this can mean in a California case

• What does the agency’s posted usage and privacy policy say about permitted uses, retention and sharing?
• Do the access records show the purpose of each query and who ran it (§ 1798.90.52(a))?
• Was the data obtained from, or shared with, an out-of-state, federal or private entity?
• Did the agency provide the required public-comment opportunity before starting its program?

A violation of SB 34 isn’t the same as a Fourth Amendment violation. Whether it affects the admissibility of evidence in a criminal case is something we haven’t verified. See grounds to suppress ALPR evidence.