On November 21, 2023, field intelligence officers within the Department of Homeland Security quietly deleted a trove of Chicago Police Department records. It was not a routine purge.
For seven months, the data—records that had been requested on roughly 900 Chicagoland residents—sat on a federal server in violation of a deletion order issued by an intelligence oversight body. A later inquiry found that nearly 800 files had been kept, which a subsequent report said breached rules designed to prevent domestic intelligence operations from targeting legal US residents. The records originated in a private exchange between DHS analysts and Chicago police, a test of how local intelligence might feed federal government watchlists. The idea was to see whether street-level data could surface undocumented gang members in airport queues and at border crossings. The experiment collapsed amid what government reports describe as a chain of mismanagement and oversight failures.
Internal memos reviewed by WIRED reveal the dataset was first requested by a field officer in DHS’s Office of Intelligence & Analysis (I&A) in the summer of 2021. By then, Chicago’s gang data was already notorious for being riddled with contradictions and error. City inspectors had warned that police couldn’t vouch for its accuracy. Entries created by police included people purportedly born before 1901 and others who appeared to be infants. Some were labeled by police as gang members but not linked to any particular group.
Police baked their own contempt into the data, listing people’s occupations as “SCUM BAG,” “TURD,” or simply “BLACK.” Neither arrest nor conviction was necessary to make the list.
Prosecutors and police relied on the designations of alleged gang members in their filings and investigations. They shadowed defendants through bail hearings and into sentencing. For immigrants, it carried extra weight. Chicago’s sanctuary rules barred most data sharing with immigration officers, but a carve-out at the time for “known gang members” left open a back door. Over the course of a decade, immigration officers tapped into the database more than 32,000 times, records show.
The I&A memos—first obtained by the Brennan Center for Justice at NYU through a public records request—show that what began inside DHS as a limited data-sharing experiment seems to have soon unraveled into a cascade of procedural lapses. The request for the Chicagoland data moved through layers of review with no clear owner, its legal safeguards overlooked or ignored. By the time the data landed on I&A’s server around April 2022, the field officer who had initiated the transfer had left their post. The experiment ultimately collapsed under its own paperwork. Signatures went missing, audits were never filed, and the deletion deadline slipped by unnoticed. The guardrails meant to keep intelligence work pointed outward—toward foreign threats, not Americans—simply failed.
Faced with the lapse, I&A ultimately killed the project in November 2023, wiping the dataset and memorializing the breach in a formal report.
Spencer Reynolds, a senior counsel at the Brennan Center, says the episode illustrates how federal intelligence officers can sidestep local sanctuary laws. “This intelligence office is a workaround to so-called sanctuary protections that limit cities like Chicago from direct cooperation with ICE,” he says. “Federal intelligence officers can access the data, package it up, and then hand it off to immigration enforcement, evading important policies to protect residents.”

