Santa Cruz, Capitola and Watsonville pledged not to cooperate with ICE. A controversial license plate reader may be undermining that promise.

Three local police departments that have pledged not to cooperate with U.S. immigration agents are using a controversial license plate reader technology that shares details with hundreds of other law enforcement agencies in California, some of which have been found to be searching the network on behalf of the federal government.

Residents might be surprised to know their cars are being logged every time they drive through certain intersections in the city limits of Capitola, Santa Cruz and Watsonville.

The Santa Cruz Police Department has eight cameras which have logged more than 458,000 vehicle license plates in the past 30 days. Capitola has 10 cameras which have scanned more than 275,000 plates in the past month. Watsonville has 20 cameras which have detected over 255,000 cars in the past 30 days.

The cameras are courtesy of contracts that all three cities have with Flock Safety. The Atlanta-based surveillance technology company sells a system of cameras that monitors and sends real-time license plate information and car-identifying details like bumper stickers to those in its network.

Founded in 2017, Flock is now used by more than 5,000 law enforcement agencies, including hundreds in California. It offers solar-powered cameras that are cheaper than fixed-camera infrastructure and an easy-to-use platform, billing itself as a “force multiplier” and a “means to do more with less.” 

Homeowners associations, schools and other organizations can also buy the cameras to track who comes into and out of their areas. Police say the cameras do not take pictures of identifiable individuals and are mostly used to identify stolen vehicles. But the extensive network allows police departments in California to access each others’ data through an interconnected database.

In the 30 days leading up to July 10, there were nearly 170 searches conducted on the Santa Cruz Police Department’s Flock network, 67 searches of the Capitola Police Department’s database, and 280 searches of the Watsonville Police Department’s system. Flock also triggered 7,600 “hotlists” hits — license plates that a Flock user has asked the system to flag — for Watsonville police in the 30 days ending July 10.

The American Civil Liberties Union and the Electronic Frontier Foundation have been vocal opponents of the technology rolling out across the nation, objecting not to the collection of license plates for tracking stolen cars but the creation of “comprehensive records of everyone’s comings and goings,” specifically targeting those people seeking sanctuary from immigration authorities or abortions in California. 

While California law prohibits local agencies from sharing license plate data with federal agencies like Immigration and Customs Enforcement (ICE), privacy advocates have identified a potential backdoor: Local law enforcement agencies are allowed to search Flock databases themselves on behalf of federal authorities, often listing vague reasons like “investigation.” 

Though Flock disabled data-sharing across state lines for California law enforcement agencies in June after media reports, critics say the system’s fundamental flaw remains: Once the data is collected by one law enforcement agency, there’s limited oversight of how other departments in California search or use it. Flock Safety did not return a request for comment.

To test the flaw, a civil liberties group, Oakland Privacy, filed a public records request for one month of the Riverside County Sheriff’s Office Flock data. The county’s sheriff, Chad Bianco, is an outspoken supporter of President Donald Trump who is running for California governor in 2026. He initially pledged to work with ICE to defy the California Values Act, which prohibits local police from helping federal immigration enforcement, before publicly saying he would follow California law. 

The privacy group found that Riverside County sheriff’s investigators had conducted four searches of Flock data between April 28 to May 30 with the reason for the searches listed as “hsinvest” — which Oakland Privacy said references “Homeland Security investigations” — despite state prohibitions. The advocacy group also flagged two searches related to U.S. Customs and Border Protection.

The Riverside County Sheriff’s Office has said the searches were for narcotics and human trafficking investigations, and not on behalf of the federal agency, according to CalMatters. The office was also sharing data with a police department in Louisiana before Flock removed the cross-state sharing feature for agencies in California, according to Mike Katz-Lacabe, director of research at Oakland Privacy. The Riverside County Sheriff’s Office did not respond to Lookout’s request for comment. 

Oakland Privacy said it is “crystal clear” that California license plate data is being accessed for federal immigration investigations. “Local governments must do some soul-searching,” Oakland Privacy wrote in a statement, “in particular those who publicly claim to defend immigrants, defend the rights of Californians, and defend civil rights.”

Santa Cruz Police Chief Bernie Escalante said he believes the Flock system has largely been a positive addition to the community for local law enforcement agencies since it makes it easier to apprehend people who are wanted on criminal charges. “I think it has been beneficial to have it because I’m not aware of anything that’s been used in a negative way,” he said.

However, he acknowledged the potential downsides, including the possibility that local license plate data could be shared with other law enforcement agencies in the state that could use it in ways that don’t align with local police departments’ policies or values, such as working with federal immigration agencies. 

“I don’t disagree it is a little bit of an issue with the Flock system,” Escalante said. “And obviously we signed onto this thing before this administration took a stance on immigration the way that they have, so this sort of nuance was not an issue when we were trying to purchase the cameras and get into a contract.”

When the Santa Cruz Police Department proposed acquiring 14 Flock Safety cameras using a $84,000 grant made available from the Department of Homeland Security in 2023, there were concerns about the loss of privacy and potential opportunity for abuse.

In response, the city council shortened the length data could be kept on Flock servers from one year to 30 days, and added language saying it cannot be shared with federal or out-of-state agencies, before approving Flock in December 2023. Even so, Mayor Fred Keeley and former councilmember Sandy Brown voted against it.

“When, at the local government level, I can push back against more and more unwanted governmental snooping on us as we go about our daily lives, I intend to do so,” Keeley wrote in an email to Lookout last week while on vacation out of the country. He did not reply to a question about whether he felt the use of the Flock data contradicts the city’s stated values.

The Santa Cruz Police Department shares Flock data with at least 307 law enforcement agencies in the state, including the Riverside County Sheriff’s Office. Capitola shares Flock data with about 269 California state and local agencies, such as California State Parks and the UC Berkeley police department. 

Watsonville public information officer Michelle Pulido did not provide information about the government agencies that are allowed to search the Flock data of the city’s police department. However, she said no federal agents see the city’s Flock data. “If they were to request access, we would deny that and, no, they cannot gain access without our authorization,” she said.

The Scotts Valley Police Department does not use the Flock system or other stationary readers. The police department operates mobile license plate readers, according to Capt. Scott Garner. A spokesperson for the department said the license plate information is not shared with anyone. 

The Capitola Police Department said it has never been asked for license plate data by any federal authority since the cameras were installed less than a year ago, but Operations Capt. Leo Moreno said the department would consider sharing it with other federal agencies for criminal investigations unrelated to immigration, and it would have to be approved by a supervisor. He gave the hypothetical example of a request by the U.S. Marshals Service for information related to a vehicle spotted in Capitola that the federal agency believed was connected with a homicide. “If we have any concern that it potentially could be associated with immigration, obviously, we would deny it,” Moreno said. 

Escalante said Santa Cruz police would refuse to knowingly share information with other police departments that intended to pass the details onto immigration officials, but officers don’t have a way of routinely monitoring how other California law enforcement agencies are using SCPD’s Flock data.

City policy allows the department to deny a request from an outside agency if senior police officials don’t believe the request is for a “valid crime.” However, Escalante said he didn’t know if the department has ever denied a search request from another law enforcement agency in California. The police are really “not aware” of what other agencies do with the data, he said. 

“I can tell you that if any agency called and disclosed that they were looking at information, either to share with federal enforcement or to conduct immigration enforcement, we would not share that information,” Escalante said. “I guess, at some point you rely on people in this profession to have a high level of integrity.”

He added that even if Santa Cruz license plate data is shared with federal agencies by other police departments in California, license plates alone don’t prove someone’s immigration status. Investigators still need to search the plate to find out who owns the car and then they need to go the extra step to physically detain the person, he said. 

Local police departments also frequently search other jurisdictions’ Flock data, according to public data and the Riverside sheriff’s department database obtained by Oakland Privacy.

Watsonville police did several searches of data from Riverside’s cameras, including listing vague reasons such as simply “investigation.” Pulido, the city’s public information officer, was not able to provide information on how many searches Watsonville police do on the Flock networks of other jurisdictions or whether other departments could search Watsonville’s system with a similarly vague reason, instead directing Lookout to file a public information request. The request, filled July 7, is still pending. 

The data also shows that Santa Cruz police searched Riverside’s Flock data more than 200 times in May. Some reasons frequently given included “ocedtf,” or “cannabis open in a veh,” or listed case numbers. An officer must provide a reason for the search if the case number is not available, according to the SCPD policy. Under California law, the requester must provide the purpose for accessing the information. 

Santa Cruz police didn’t respond to questions to clarify what “ocedtf” stands for, though it closely matches the acronym for Organized Crime Drug Enforcement Task Force, a federal Department of Justice program. 

An audit of the searches conducted by the Santa Cruz Police Department in the Flock system will be done for the first time this fall, Escalante said. However, the audit won’t examine what other departments are searching for in Santa Cruz’s database and if the reasons for those searchers are valid, according to Escalante.

Peter Gelblum, chair of the Santa Cruz County ACLU chapter, said the Flock Safety system reminds him of Palantir, a company with deep connections to the federal government that centralizes data from the military and other departments, and highlights the dangers of technology firms that compile databases from multiple sources and then make them accessible to many users.

“Everything is available, and that’s sort of the fundamental problem that is unavoidable with [license plate cameras] and any other kind of surveillance technology,” Gelblum said. “Once the data is there, once the data is collected, it’s vulnerable to being accessed by people who shouldn’t have it.”

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FOR THE RECORD: This story has been updated to add detail from the Scotts Valley and Watsonville police departments.

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