Exclusive: Inside Imperial County’s ALPR Network: Flock Cameras, Hidden Readers and Data Sharing

IMPERIAL COUNTY, Calif. - Roughly 180 automated license plate readers across Imperial County are photographing passing vehicles, reading their license plates and logging where and when they traveled. Some of them, the Sheriff's Office acknowledges, may be hidden from public view.

Records obtained by 760 News Media show the cameras are part of a countywide program that has run since 2017 under a committee that includes a representative of the U.S. Border Patrol. The El Centro Police Department is the program's designated host agency, responsible under the agreement for storing and sharing the data. The two member cities that have released their sharing lists each send what their cameras collect to more than 300 law enforcement agencies, all of them in California.

The records also show that in one recent month, officers in one Imperial Valley city searched the system 155 times without recording a single case number, something the county's own regional agreement requires.

Where the cameras are

As of Sept. 24, volunteers tracking the devices through DeFlock, a crowdsourced project built on OpenStreetMap data, had mapped approximately 90 cameras in El Centro, 46 in Brawley (Brawley's own Flock transparency page lists 41), 13 in and around Calexico, 4 in Imperial, 3 in Holtville, 2 each in Heber, Seeley, Salton City and Bombay Beach, and about 18 in unincorporated county areas.

Those numbers are a floor, not a ceiling. The map reflects only cameras someone has found and logged. The El Centro figure is approximate because several mapped points appear to be duplicates.

The public map also does not capture the county's other fleet. A 2017 regional agreement lists 47 vehicle-mounted license plate reader systems distributed among five agencies, plus two radar speed trailers with cameras built in.

How the system works

The devices work the same way whether they are bolted to a pole or mounted on a patrol car. A camera photographs a passing vehicle, software converts the license plate into text, the plate is checked against lists of stolen and wanted vehicles, and the image is stored along with the time and place it was taken in a database police can search later.

Lt. Joseph Conkey, public information officer for the Imperial County Sheriff's Office, said the cameras do not record video.

"The cameras don't actually record. They just take pictures of license plates," Conkey said. The images capture the rear of a vehicle, and sometimes the front, showing the plate along with the vehicle's make, model and color.

Deputies can also search without a plate. Conkey said the system can find vehicles by description, giving the example of a 1990s gray Toyota Tacoma, though he said details such as a dent may not appear because the images focus on the bumper.

When a plate matches a hotlist, such as a stolen vehicle or an Amber or Silver alert, the system alerts deputies. Conkey said the Sheriff's Office uses the cameras regularly in investigations ranging from homicides to hit-and-runs and burglaries. He did not have figures on how many cases the system has helped solve.

The program behind the cameras

A Memorandum of Understanding approved by the Imperial County Board of Supervisors on Oct. 10, 2017, established the Imperial County Regional License Plate Recognition Program. Its member agencies are the Brawley, El Centro, Imperial and Westmorland police departments and the Imperial County Sheriff's Office.

The agreement states the program "is managed by a Regional ALPR Committee, comprised of a representative from each of the Member Agencies and a representative from the United States Border Patrol."

The MOU does not state that Border Patrol has access to data collected by the system. It places a federal immigration enforcement agency on the body that governs the program. No local agency has yet answered whether any federal agency can search the data.

We have reached out to the city of El Centro for comment, but I have not yet heard back.

The agreement designates the El Centro Police Department as the Host Agency, responsible for "storage of ALPR Data and sharing of ALPR Data," and the sole point of contact for outside agencies seeking access.

The original equipment was purchased with federal Homeland Security money through Operation Stonegarden, a border security grant program. The agreement says equipment was distributed with consideration given to "the needs of the United States Border Patrol as it relates to furthering the mission of Operation Stonegarden."

The agreement also grants the committee authority to add new agencies or new information sharing systems to the program, and states that "such agreements will not require further review or approval by Member Agencies."

Cameras out of sight

The 2017 agreement explicitly allows cameras to be hidden. It states ALPR devices can be "concealed within stationary objects (i.e. traffic barrels, pole cameras, etc.)" or "concealed within portable traffic warning devices (i.e. sign boards, speed trailers, etc.)."

Asked whether any such cameras operate in Imperial County, Conkey said the majority are in public view, but that "there may be some out there that are hidden from the public."

He did not say how many, where they are or which agency operates them.

In February, the nonprofit newsroom inewsource reported that the Electronic Frontier Foundation had mapped more than 40 hidden license plate readers across southern San Diego and Imperial counties, concealed in orange construction barrels and two-wheeled trailers along highways. EFF said they may belong to Customs and Border Protection or the Drug Enforcement Administration but had not determined ownership.

How the Flock cameras arrived

The fixed cameras now visible on Valley streets came later, through a different funding stream.

A Calexico staff report says members of a body called the Regional License Plate Reader Group met twice, on Oct. 4 and Oct. 13, 2022, to decide how to spend High Intensity Drug Trafficking Area discretionary money on what the report calls the IVDC Regional LPR Program. The report puts the total available at "approximately $444,419.00 from the 2020 and 2021 discretionary grant awards" and says that at both meetings "all members present agreed upon a unanimous vote to fund the project." The city council votes that followed were each city approving its share of a decision already made.

Imperial's council took up an agreement for four cameras in December 2022, on an item submitted by police Capt. Max Sheffield describing them as placed near busy intersections, funded through HIDTA for two years, with "no fiscal impact to the City of Imperial." Calexico's council took up its own agreement on Jan. 18, 2023, for four cameras under a $23,000 contract that HIDTA had already funded, also at no cost to the city.

After the grant period ended, Imperial began paying directly. Records the city released show Flock billed it $23,000 in January 2023 with nothing due, then $12,000 in January 2025 and $12,000 in May 2026. The per-camera price rose over that period from $2,500 a year to $3,000.

Three retention policies, none matching practice

The ALPR policy the Imperial County Sheriff's Office produced to 760 News Media states that license plate data "should be stored for a minimum of two years." That document, numbered Policy 470, carries a revision date of December 2016 and was attached to the back of the regional MOU the office released.

The policy manual currently posted on the Sheriff's Office website says something different. Dated December 2020, it contains the same policy renumbered as Policy 468, with the minimum cut in half, to one year.

Assistant County Counsel Mistelle Abdelmagied wrote on Sept. 18 that Sheriff's Office data was "originally set to be stored for one year," but that the office "no longer pays for that storage option so storage is limited to 30 days."

The Imperial and Calexico police policies each say a minimum of one year.

In practice, none of those numbers applies. The Flock agreements these agencies signed set "a thirty (30) day retention policy for all products except Wing Replay." Flock lowered its recommended default again in August 2026, to seven days, though it said existing customers keep the retention they already have.

Stricter rules for the cameras that record video

Every one of the five Imperial County law enforcement agencies that operates license plate readers holds its other cameras to a standard it does not apply to these.

Policy manuals from all five agencies contain a section governing public safety video surveillance systems. In nearly identical language, all five require that any public area under camera surveillance be marked with conspicuous signs informing the public that the area is under police surveillance. All five require a written log recording who was given access to the footage, which agency they work for, who authorized it and what they viewed. All five bar the use of those cameras to harass, intimidate or discriminate against any individual or group. And all five require the chief or the sheriff to conduct an annual review of the system's cost, benefit and effectiveness.

None of the five imposes any of those requirements on automated license plate readers. There is no signage requirement in any of them. There is no specified access log. Only El Centro's ALPR policy lists prohibited uses. Four of the five say only that ALPR audits "should be conducted on a regular basis," without naming an interval or who conducts them.

All five manuals are produced by Lexipol, a private company that sells template policies to law enforcement agencies nationwide.

What the Sheriff's Office says to residents

Conkey said residents should understand that anyone in public can be photographed, whether by traffic cameras, Flock cameras "or somebody standing on the street corner filming you."

He said the cameras are not there to track people's movements but to help solve crimes, and that a resident who becomes a victim could one day benefit from them.

"Just think of the Flock cameras as an eye in the sky to help us help you," he said.

Where the data goes

A document generated Aug. 25 shows the city of Imperial shares its license plate data with 357 organizations. All 357 are in California. They include the Los Angeles, San Francisco, San Jose, Oakland and San Diego police departments, sheriff's offices across Southern California, the California Highway Patrol, the state Department of Corrections and Rehabilitation and the Imperial County District Attorney.

Brawley's sharing list, published on its Flock transparency portal, runs to 320 organizations. All 320 are California agencies.

Imperial shares its data with 357. In both cases, all of them are California agencies. imperial's records also show data moving the other direction. Five agencies share their license plate reads into Imperial's system without Imperial sharing back, including two in Georgia.

Both lists include the Northern California Regional Intelligence Center. Imperial's also includes the Western States Information Network.

Those two organizations were at the center of what happened in San Francisco. On June 18, 2026, San Francisco police told the city's Police Commission that an audit had found roughly 300 improper queries of the department's Flock network, and that NCRIC had run searches on behalf of outside agencies and shared information with WSIN. The department disabled both organizations' access. Its chief said the audit found no queries tied to immigration enforcement, and the department did not end its Flock contract.

There is no evidence in the records released that Imperial's or Brawley's data traveled that path. The pathway identified in San Francisco exists in Imperial's sharing list.

No federal immigration agency appears on either list.

Both readers at Calexico's ports of entry are identified in OpenStreetMap data as operated by U.S. Customs and Border Protection, cross-referenced to a dataset maintained by the Electronic Frontier Foundation. California's license plate law reaches only state and local agencies.

What the search logs show

The 2017 regional agreement requires case numbers, but logs from two departments show that standard isn't consistently met.

The agreement sets the same standard. Section 7.6 states that "each transaction in an ALPR repository is to be logged, to include a Case Number, and an audit trail created."

Logs from two Imperial Valley departments show that standard is not consistently met.

Those two departments are the only ones whose search records 760 News Media has been able to obtain. Imperial released its log in response to a public records request. Brawley publishes its own on a public portal. The rest of the agencies have not yet publicly released the audits.

Brawley is the only agency in Imperial County that publishes its license plate searches at all. Its transparency portal posts a rolling record of every query officers run, and it is the reason a second department's logs could be examined for this story without waiting on a records request.

Imperial's log covers every search its officers ran between July 26 and Aug. 24. It records 155 searches by seven officers. Every search lists a reason, most commonly motor vehicle theft. Nine cite traffic infractions, which Flock lists as a prohibited use on its own transparency portals. Not one of the 155 records a case number. The field exists and is empty in every row.

We have reached out to the Imperial Police Department for comment but have not yet heard back.

Brawley's log shows the opposite gap. Of 118 searches between Aug. 24 and Sept. 21, 91 have no reason recorded at all. The field is blank in 77 percent of them. The same portal states that all system access requires a valid reason and again, no case numbers.

A reason is a label. A case number is what ties a search to an actual investigation and allows anyone reviewing the log afterward to confirm it was justified. Neither department's log contains one.

Brawley's log also records how many networks each search reached. Most queried between one and 140. Eight reached more than 500. The department has not explained what the number counts.

Imperial's log shows patterns its stated reasons do not explain. On one evening in August, officers ran 34 searches on a single license plate over roughly eight minutes, recording three different reasons for the same vehicle.

A statewide reckoning

Other California communities are pulling back. Santa Cruz, Mountain View and El Cerrito have ended their Flock contracts this year, and Grass Valley police suspended their license plate readers in August.

In October 2025, Attorney General Rob Bonta sued the city of El Cajon, alleging it shared license plate data with out-of-state and federal agencies in violation of SB 34. In Chico, a ChicoSol investigation found police had given roughly 20 federal agencies and more than 80 out-of-state agencies access to data from the city's Motorola cameras, including ICE.

Flock's public pages say its cameras capture vehicles rather than faces, that agencies own and control their data, and that no secret federal access exists. The Sheriff's Office's own 2022 agreement with Flock states that Flock and its licensors "retain all right, title and interest" in the service and "any Recordings or data provided by Flock," and requires the Sheriff's Office to notify Flock of any public records request so the company can oppose disclosure.

What we asked, and what we know

760 News Media filed public records requests with five law enforcement agencies asking each how much they have spent, how many cameras they operate and where, what policy governs their use, and whether the data is shared with any state, federal or out-of-state agency.

City of Imperial: Responded. Produced invoices, its policy, the 2022 council item, a month of search logs and its list of sharing partners. The most complete production of any agency.

Imperial County Sheriff's Office: Responded Sept. 18, on a rolling basis. Produced the 2017 regional MOU, its ALPR policy and its 2022 Flock agreement, and made its public information officer available for an interview.

Calexico: Partially denied and closed. The city produced its contract, council materials and ALPR policy, and reported no correspondence with the state Department of Justice. On Sept. 17 it denied the request for camera numbers and locations, citing an exemption for information security records, and closed the request without addressing its data-sharing records or search logs.

El Centro: No records produced. The city received the request Aug. 12 and has extended its deadline four times, most recently on Sept. 22, the day it had promised production. It now anticipates producing records on or about Oct. 6, 55 days after receipt. The city has not stated whether it possesses responsive records or claimed any exemption. Its ALPR policy, one of the items requested, is published on the city's website, and four of its camera locations were filed with the state in March. El Centro is the designated host agency that stores license plate data for the countywide program and has more mapped cameras than any other city in the county.

Brawley: No records produced. The department received the request Aug. 4. The city attorney said Aug. 13 that records were being gathered and he did not anticipate withholding any, but the city has not provided a production date.

Imperial County: No response to the separate county request submitted Aug. 26.

Coming next

A second report will examine the Regional ALPR Committee, who sits on it, how the program has expanded since 2017, and what the remaining agencies' records show.