Los Altos Police Department ALPR usage

October 13, 2025

Table of contents

This report is based on data obtained via California Public Record Act requests 25-312 and 25-402 for data related to the ALPR system operated by the Los Altos Police Department (hereafter LAPD). It covers the period March 1, 2024 through August 31, 2025.

The Transparency portal.

1:1 Sharing audit

Under 1:1 Sharing, each agency decides which other agencies can access its data. Agency A can share with agency B without B sharing with A.

LAPD and X allow reciprocal searches: 186 agencies, including 9 neighbors:

LAPD allows searches, but X does not: 34 agencies, including 1 neighbor:

LAPD does not allow searches but X does: 84 agencies, including 2 neighbors:

Sharing outside California

Prior to February 12, 2025, there are numerous queries from agencies outside California.

3,804 agencies outside California accessed the LAPD data, with 214,555 cases / 1,482,641 queries. The 25 most active agencies:

Some are federal agencies, but with few queries:

These queries are clear violations of California SB 40, as California state and local law enforcement agencies have been reminded by the California Attorney General in 2023.

Sharing via Statewide lookup

LAPD participates in Statewide lookup. This allows California agencies to search the LAPD data without any prior agreement on sharing, but limits the searches to full license plates.

109 agencies without 1:1 Sharing have accessed the LAPD data since February 12, 2025.

Organization audit: number of queries

Most of the 6,066 queries made by LAPD involve, among others, cameras controlled by the LAPD. 219 queries involve only non-LAPD cameras.

The number of cases and queries is relatively stable:

Organization audit: number of agencies and cameras

The first column is the number of agencies that queried the data, which by construction must be 1 in an organization audit.

The second column is the maximum number of cameras involved in a query. While most agencies operate a relatively small number of cameras, they can search data captured by other agencies.

The next column, “% 0-100” is the percentage of queries that involved less than 100 cameras. Similarly, the following columns are the percentages for 100 to 1k cameras, 1k to 10k cameras and more than 10k cameras respectively.

In the August-November 2024 period, there are few queries with a large number of cameras, so the maximum number of cameras is subject to wide variations. The low number in January 2025 was caused by a systemic problem with the Flock system. It remains that over the long term, more and more cameras are accessible.

If we ignore those months, it is clear that there is a bimodal distribution of the number of cameras: either a few cameras are searched (less than 100), or there is a broad search, with more than 1,000 cameras.

Also apparent is the increase in the proportion of broad queries over the last six months, roughly from 30% to 60%.

Organization audit: personnel

The LAPD elected to redact the user names from the both the Organization and Network audits.

Network audit: number of queries

In addition to the situation over the whole audited period, we also look at the period since February 12, 2025, when sharing outside California stopped:

Over the recent period, that amounts to one query every 10 seconds, and one case every 90 seconds.

The number of cases has been steadily increasing each month, with a reset when sharing outside of California was stopped:

It is also worth noting that for every 1,000 queries made on LAPD data, there is only 1 made by LAPD, the 999 others are made by other agencies (roughly).

Network audit: number of agencies and cameras

See this previous section for the meaning of the columns.

As we have seen in the previous section, the queries by other agencies vastly dominate. From the point of view of those agencies, LAPD is just one of many agencies, more or less geographically distant. When LAPD’s data is searched, there are probably many other agencies searched as well, and therefore many cameras involved, hence the high proportion of broad searches.

Top agencies accessing LAPD data

The 25 agencies with the largest number of cases involving LAPD data since February 12, 2025:

Our neighbor agencies, since February 12, 2025:

Potentially problematic queries

The Flock system filters queries by keywords, in an attempt to avoid uses prohibited by SB 40, but we do not know what those keywords are.

Here are cases/queries with “ICE”, “DHS”, “HSI” (which can stand for Homeland Security Investigation), “CBP”, “FBI”, “ATF”, “AFT” (typo for “ATF”), “Marshal”, “Marshals”, “Marshall”, “Marshalls”, “border”, or “immigration” as a word in the case number or reason.

The cases since February 12, 2025:

(The August 6, 2025, Los Altos Town Crier article mentions “Four June Riverside County Sheriff’s Office network searches”. Those form a single case, on June 30.)