Guns are pictured in a file photo. (WTTW News)

More than 1,100 Glock semiautomatic pistols have been converted into illegal machine guns and used in a wide variety of crimes, including homicides, carjackings and robberies, during the past two years in Chicago, Mayor Brandon Johnson said Wednesday.

Glock should be banned from selling those guns to Chicagoans and forced to pay for the harm the pistols have caused, according to a new lawsuit filed by the city’s lawyers that will test a new state law designed to crack down on gun manufacturers.

“The city of Chicago is encountering a deadly new frontier in the gun violence plaguing our communities because of the increase of fully automatic Glocks on our streets,” Mayor Brandon Johnson said. “Selling firearms that can so easily be converted into automatic weapons makes heinous acts even more deadly, so we are doing everything we can in collaboration with others committed to ending gun violence to hold Glock accountable for putting profits over public safety.” 

Glock could prevent the guns it sells to non-law enforcement officers from being modified into illegal machine guns, “but refuses to do so,” according to a statement from the mayor’s office.

Glock’s semiautomatic pistols can be converted to illegal machine guns with an auto sear – a cheap, small device commonly known as a “Glock switch,” according to the lawsuit. That violates the Firearms Industry Responsibility Act, which Gov. J.B. Pritzker signed into law in 2023 to hold gun companies accountable for conduct that endangers the public. 

A spokesperson for Glock did not immediately respond to a request for comment.

The so-called Glock switches are the size of a quarter and can be purchased online for around $20 or manufactured at home using a 3D printer. Once installed, the switch allows pistols to fire up to 1,200 rounds per minute – a rate as fast as or faster than many fully automatic firearms and machine guns used by the United States military, according to a statement from the mayor’s office.

Federal officials reported a 400% increase in recoveries of illegally modified machine guns from 2020 to 2021 and a 570% increase in the number of modified Glocks recovered from 2017 to 2021, as compared to the previous five-year period, according to a statement from the mayor’s office.

The lawsuit asks a judge to find that “selling a weapon that can be so easily converted to an illegal machine gun and failing to take reasonable steps to prevent or mitigate the problem is an unfair business practice, is negligent, and creates, maintains, and contributes to a public nuisance,” according to a statement from the mayor’s office.

Contact Heather Cherone: @HeatherCherone | (773) 569-1863 | [email protected]