Investigations
Illinois State Police Keeps Data on Suspected Gang Members. ICE Has Access
Despite an Illinois law prohibiting data sharing agreements between state law enforcement agencies and federal immigration authorities, the Illinois State Police makes available the names and information of individuals who they deem to be gang members to U.S. Immigration and Customs Enforcement.
Illinois and its leaders have positioned the state as a protector of immigrants’ rights as the Trump administration has sent hundreds of migrants who are said to be gang members, often with limited evidence to support those claims, to a mega-prison in El Salvador.
A 2017 state law, the TRUST ACT, explicitly prohibits Illinois law enforcement agencies from entering into or maintaining agreements that would provide federal immigration authorities direct access to electronic databases. There is an exception if the agency is presented with a federal criminal warrant or if it’s otherwise required by federal law.
But according to agreements obtained by WTTW News, the Illinois State Police has shared data with ICE through a statewide computer system, the Law Enforcement Agencies Data System (LEADS), since 2008, including criminal history data and its gang member file, which could contain citizenship information, according to the LEADS manual.
An image of a LEADS gang member file displays a line for “citizenship” information and instructions outlining how that information should be entered.
An example of an Illinois State Police gang file entry form is show within a presentation document from the agency. (Illinois State Police)
DHS Enforcement and Removal Operations, which oversees the immigration enforcement process, including identification, arrest, detention and removals, entered into a LEADS Agreement in 2024, according to records obtained by WTTW News.
When asked whether this agreement potentially violates the TRUST Act, a spokesperson for Illinois Attorney General Kwame Raoul’s office, which oversees compliance and enforcement of the law, responded that they have not reviewed the agreements, so they do not have a comment. After WTTW News provided the agreements to the office, they did not respond to a request for comment.
LEADS operates as a statewide data system used to share crime statistics and other law enforcement information among various agencies. Among the data Illinois State Police makes available in the system is information about individuals’ alleged gang ties. An unknown number of other local law enforcement agencies across the state may also be sharing information about alleged gang affiliations with immigration agencies through the same system.
The potential for federal immigration enforcement agencies to use noted gang affiliation as justification for deportation action has civil liberty groups concerned.
“They could be swept up off the street and disappeared, that’s the harm,” Ed Yohnka, communications director for the ACLU of Illinois, said of individuals who may be listed in Illinois State Police’s gang file. “And the harm could be based on nothing more than a third-party assertion.”
Illinoisans can land in the LEADS database for wearing “distinctive emblems” or tattoos, according to the LEADS manual.
Gov. JB Pritzker has vigorously defended the TRUST Act, which more generally prohibits state and local law enforcement from assisting federal immigration agents.
“All our agreements with law enforcement agencies are a standard criminal justice information sharing agreement. LEADS is not designed to collect immigration status information. Any agency, including ICE, using LEADS for purposes in violation of state or federal law would be violating the terms of our standard LEADS agreement. The Pritzker administration’s operation of LEADS is fully in compliance with state and federal law,” said Alex Gough, Pritzker’s press secretary.
Next week, Pritzker will testify to Congress about these laws designed to protect undocumented immigrants as the Trump administration is attempting to strip so-called sanctuary cities of all federal funding. The Trump administration is currently suing Pritzker, alongside Chicago and Cook County officials, over the TRUST Act and the city’s Welcoming City ordinance, claiming it’s obstructing federal immigration enforcement.
Pritzker has yet to announce whether he will run for a third term as Illinois governor and is widely considered to be weighing a run for president in 2028.
The Use of Gang Files
The Illinois State Police’s gang file has avoided the high level of scrutiny that Chicago’s own gang database received, which was discontinued in 2023 after investigators found that it disproportionately targeted Black and Latino Chicagoans, and contained numerous errors.
From 2009 through 2018, federal immigration agencies searched the Chicago Police Department’s gang database at least 32,000 times, according to a report from the city’s Office of Inspector General. While Chicago’s now-defunct gang database was active, it caused immigration officials to keep a man wrongly accused as a gang member for 10 months in detention.
Cook County Sheriff’s Office spokesperson Matthew Walberg said they do not enter gang member data into LEADS. The office ended the use of its gang database in 2019. Historically, the office didn’t typically enter gang member data into LEADS, Walberg said.
The Chicago Police Department did not respond to questions on whether it is still submitting gang data to LEADS, or if previously entered past gang member information is still available.
While ProPublica reported that there were more than 90,000 people in the gang member file in 2018, Illinois State Police officials were not able to provide how many people are currently listed in the gang member file.
In April, investigative news outlet New York Focus reported that New York State Police currently provide ICE with access to a gang database; their State Police maintain a Gang Reporting and Intelligence Program Database that’s added to the FBI’s National Crime Information Center Gang File, which is then accessible to ICE through the agency’s Investigative Case Management System.
But in Illinois, the path for ICE to access the gang member file is more direct.
“Any law enforcement agency that uses LEADS would be able to see if an individual was included in the gang member file if that law enforcement agency ran an inquiry on that specific individual,” Melaney Arnold, spokesperson for the Illinois State Police, said in an email.
When asked how and how often the gang member file is used by ICE, Arnold directed WTTW News to ask ICE how often it uses LEADS and how.
When asked how often the Department of Homeland Security has used Illinois’ LEADS and whether it has used gang member information in immigration proceedings or deportations, representatives responded that they “are confident in our law enforcement’s intelligence” and that they “aren’t going to share intelligence reports and undermine national security.”
Even without the LEADS Agreement, the Department of Homeland Security has had some access to information from local law enforcement despite the TRUST Act.
Federal immigration authorities will request data from local agencies, who can share information only when they are presented with a federal criminal warrant or required by a specific federal law.
In 2023, Illinois received 503 data requests from the Department of Homeland Security according to the Illinois Office of the Attorney General. Of those, 58 were reported as accepted by local law enforcement agencies. The Attorney General’s office determined that the accepted inquiries were largely Freedom of Information Act requests from federal immigration authorities for data like arrest reports or booking photographs.
How Gang Affiliation Is Tracked
There’s broad criteria to be categorized as a gang member in LEADS. Some of these include tattoos, the wearing of distinctive emblems of a specific gang not for sale to the general public or the use of signals or symbols from a specific gang. Someone could also self-identify as a gang member or could be identified by an informant, according to the LEADS manual.
Once someone is identified as a gang member, they’re entered into LEADS. The LEADS Gang Member File is a statewide application that provides officers with instant access to information on individual membership in known gangs.
A criminal street gang is defined in a LEADS manual as any ongoing organization, association in fact or group of three or more persons, whether formal or informal, “having as one of its substantial activities the commission of criminal gang activity and whose members individually or collectively engage in or have engaged in a pattern of criminal gang activity.”
LEADS purges Gang Member records after five years from the date of entry, according to a user manual. The “once a gang member, always a gang member” axiom is not acceptable, the manual states.
But gang databases have often been widely inaccurate and riddled with error, Yohnka of the ACLU said.
“Those systems were often built on the ideal of, you know, information sharing without necessarily discernment about the accuracy of the information,” Yohnka said of gang databases.
The Chicago Police Department’s now-decommissioned gang database was “deeply flawed,” says a 2021 Chicago Inspector General report.
Approximately 95% of the at least 134,242 Chicagoans listed as gang members were Black and Latino. Ages on the database ranged from zero to 117 years old. CPD did not have a process for individuals to contest or appeal gang designations or to amend inaccurate gang information.
In 2019, CPD promised to fix those errors, launching a new system of tracking gang members. But that system was also flawed, as it was still using data from the prior database, a 2021 follow-up report found. In 2023, a commission overseeing CPD voted to permanently scrap the launch of a new system.
For immigrants, gang designation can have dire consequences, like deportation.
In the Trump administration’s case, they’ve used alleged gang ties to justify deporting hundreds of people, largely Venezuelan men claimed to be members of the gang Tren de Aragua. Few of those deported appear to have any clear, documented links to the gang. Despite the disputed significance of tattoos, the administration has used tattoos of crowns, clocks and other symbols to justify gang ties and deportations.
Yohnka said the LEADS agreement could lead to horrific consequences and that the Illinois attorney general, who enforces the TRUST Act, and law enforcement agencies should ensure the act isn’t circumvented.
“I think this is a really important area, you know, for law enforcement and the attorney general to work together on to ensure that we’re really abiding by the spirit of the TRUST Act, and that we’re not putting people at risk,” Yohnka said.
Note: This article was published June 2, 2025, and updated with video June 5, 2025.
Contact Blair Paddock: @blairpaddock | [email protected]
