Chicago Police typically don't share information regarding undocumented citizens with federal immigration agents, except in a few instances, like if they are in the police department's gang database. View Full Caption Facebook/Immigration and Customs Enforcement

CHICAGO — As President Donald Trump has promised to crack down on cities that protect undocumented immigrants from deportation, Chicago has recommitted to its "sanctuary city" status and kept city police from cooperating with Immigration and Customs Enforcement agents.

But that doesn't mean the agencies don't cooperate in some cases.

One way the Chicago Police Department does cooperate with ICE is by sharing its gang database, which keeps track of city residents who've been identified as having gang affiliations. ICE agents use the database to look for alleged gang members in the city.

People in the Police Department's gang database are not protected by the Welcoming City Ordinance, which lays out the rules for Chicago's sanctuary city status.

Wilmer Catalan-Ramirez, a mechanic and undocumented immigrant living in the Back of the Yards neighborhood, claimed in a lawsuit filed Monday against the Police Department, ICE and other agencies that he was placed in the Police Department's gang database erroneously and without his knowledge.

Catalan-Ramirez said he's not a gang member and never has been.

But when the list with his name on it was handed to ICE by police, Catalan-Ramirez says it set off a "nightmarish chain of events" that ended in an illegal home raid and jail time after he was wrongly labeled a gang member by police, his lawyers said.

On March 27, six ICE agents raided Catalan-Ramirez's house without a warrant while his wife and young son were home, demanding to know where "guns and drugs" were and slamming him to the ground and fracturing his left shoulder, according to the lawsuit.

While Catalan-Ramirez would have been protected under Chicago's Sanctuary City status, his inclusion on the gang list removes those protections, leaving him vulnerable to deportation.

Other exceptions to the rule, which usually prohibits the Police Department from sharing non-crime-related information with ICE, say it's OK for the Police Department to collaborate with ICE if the person in question has an outstanding criminal warrant, has been convicted of a felony, or is a defendant in a criminal case where a judgment has not been entered and a felony charge is pending.

Databases 'riddled with false information'

The information-sharing relationship between Chicago police and federal immigration agents hinges on the credibility of the database, which some say is questionable.

Catalan-Ramirez is among countless Chicagoans who have claimed they were wrongly identified as gang members by police.

Catalan-Ramirez's lawyers called the Police Department's identification system "arbitrary, over-inclusive" and "riddled with false information."

"Many people are included in the Gang Database who are not in fact members of any street gang," his attorneys said.

Catalan-Ramirez is a mechanic and the primary breadwinner for his wife and 3-year-old son, according to the lawsuit.

His attorneys said he "is not, nor has he ever been a member of a Chicago street gang."

Catalan-Ramirez's attorneys argue not only should their client have never wound up on the list, but that the Police Department's method of identifying gang members violates his constitutional rights.

The lawsuit alleges "that the manner in which CPD gathers and disseminates false information about gang membership violated the Illinois Civil Rights Act, which prohibits racial and ethnic discrimination," by disproportionately targeting black and Latino men.

The Police Department declined to comment.

On Thursday, ICE said Catalan-Ramirez was still in the agency's custody awaiting "removal proceedings."

ICE described Catalan-Ramirez as "a previously deported criminal alien from Guatemala" and said it targeted him March 27 as part of "an ongoing enforcement action targeting gang members and gang associates."

Sanctuary City protection threatened

Though police have guidelines in place to determine who ends up in the gang database — factors can include self-admission of gang affiliation, observation of certain hand gestures and sometimes where a person lives or has been known to hang out — the inexact science of identifying gang members ends up casting too wide a net, critics say.

For undocumented immigrants who would otherwise be protected under city ordinance, the stakes of making a mistake are especially high.

According to the lawsuit, Catalan-Ramirez was put into the gang database sometime in 2014 or 2015, but police didn't notify him that he had been added, nor did they provide an explanation for why he was included.

Without knowing he was considered a gang member by police, Catalan-Ramirez says he missed an opportunity to prove otherwise.

“Chicago is therefore not a sanctuary city for those individuals like Mr. Catalan-Ramirez who have been falsely labeled by CPD as a gang member and then subsequently targeted by ICE because CPD shared this false information,” his lawsuit states.

Xanat Sobrevilla, an organizer with Organized Communities Against Deportations, said that Catalan-Ramirez's case was “an example of how local city policies, such as the Gang Database, put immigrant communities in the path of Trump’s deportation machine."

“If the City of Chicago truly wants to be a sanctuary city where immigrants can seek safe refuge, it should stop sharing its gang database with ICE and inform ICE the database is rife with inaccuracies and is not a legitimate law enforcement tool.”