(The Center Square) – An Illinois lawsuit has led Colorado Attorney General Phil Weiser and attorneys general from 11 other states and the District of Columbia to notify gunmaker Glock to preserve 37 years of documentation regarding its handguns.

Earlier this month, the city of Chicago filed a lawsuit against Glock alleging the company failed to change the design of a pistol. Chicago claims Glock knew a do-it-yourself “switch” could make the handguns a “machine gun” and resulted in a “proliferation of illegal machine guns.”

Illinois passed a law last year allowing lawsuits against the firearms industry, which is being challenged in federal and state-level courts. Chicago’s lawsuit claims Glock had knowledge its guns could be adapted to become a “machine gun.”

“Through these practices, Glock knowingly creates, maintains and contributes to a condition in Chicago that endangers the safety and health of the public,” the lawsuit states.

The letter from the attorneys general requests Glock to preserve all documentation from 1987 to the present regarding its semi-automatic handguns, the public safety impact of its handguns, and any knowledge of federal and state laws pertaining to firearm modifications.

“Colorado enacted a large capacity magazine law to protect individuals from mass shootings,” Weiser said in a statement. “When it comes to preventing such tragedies, we will continue to enforce our laws and work to save lives. In investigating this matter, cracking down on ghost guns, and in implementing our red flag law, we are remaining vigilant in doing just that.”

The Chicago lawsuit claims the modification to Glock’s pistols allows the guns to fire up to 1,200 rounds per minute, similar to the speed of fully automatic firearms and machine guns used by the U.S. military. It also noted the Bureau of Alcohol, Tobacco, Firearms and Explosives reported a 400% increase in recoveries of illegally modified machine guns from 2020 to 2021 and a 570% increase in the confiscation of switches from 2017 to 2021 as compared to the previous five-year period.

If Chicago wins in court, the letter warns Glock it will face similar litigation in their states.

“If the City’s factual allegations are true, your conduct may also involve violations of our states’ laws,” the letter said. “We will not hesitate to enforce our laws when they are violated.”

Earlier this week, the National Shooting Sports Foundation filed a 43-age motion in a district court requesting a review of the Chicago lawsuit.

Other states joining Colorado in the letter to Glock are Connecticut, Delaware, Massachusetts, Michigan, Minnesota, New Jersey, Oregon, Pennsylvania, Rhode Island, Vermont, Washington, and the District of Columbia.