Leaving the Door Wide Open: Flock Surveillance Systems Expose Washington Data to Immigration Enforcement

This report reveals that at least eight Washington state law enforcement agencies which employ automated license plate reader networks purchased from the private company Flock Safety had enabled direct sharing of their networks with U.S. Border Patrol at some point during 2025, effectively opening the “front door” for Washingtonians’ movements to be scrutinized by federal immigration enforcement agents. Flock system audits obtained via public records requests and analyzed by UWCHR researchers also show that an additional ten police departments in Washington state were exposed to searches of their license plate reader networks by Border Patrol despite not explicitly sharing access with the federal agency. 

Detailed report findings include:

• Flock Safety automated license plate reader (ALPR) networks have become increasingly common in Washington state, reportedly employed by as many as 80 public agencies and additional private organizations.
• At least eight Washington state law enforcement agencies enabled direct, 1:1 sharing of their networks with U.S. Border Patrol at some point during 2025. These agencies include Benton County Sheriff’s Office and police departments in the cities of Arlington, Auburn, Lakewood, Richland, Sunnyside, Wenatchee, and Yakima.
• Flock audits reveal apparent “back door” access by U.S. Border Patrol to the networks of at least ten Washington police departments which did not explicitly authorize Border Patrol searches of their network data. These agencies include the following police departments: Black Diamond, Centralia, Chehalis, East Wenatchee, Eatonville, Ellensburg, Grandview, Mukilteo, Prosser, and Renton.
• Flock audits reveal limited cases of law enforcement agencies in Washington state conducting “side door” searches on behalf of federal immigration enforcement agencies, likely in violation of the Keep Washington Working Act’s restrictions on collaboration with civil immigration enforcement activities. The report also documents numerous similar searches by out of state law enforcement agencies with access to Flock networks in Washington state. 
• Discrepancies between Flock audits and other documentation make it impossible for independent researchers to determine the current scope of local organizations’ access and exposure to searches by other Flock users nationwide. In addition, several agencies, including Arlington, Everett, Kent, Medina, Sedro-Wooley, and Tukwila, fully or partially denied public record requests for Flock audits, asserting that they had never consulted the audits and that they therefore do not constitute public records.