Illinois banned unmarked “ghost guns” Wednesday after a number of deadly shootings renewed nationwide concerns about gun violence.

“Ghost guns” are untraceable weapons sometimes made from a kit, assembled with parts purchased online or by 3D printers that do not require a background check and lack serial numbers which makes it difficult to trace the owner.

Gov. J.B. Pritzker signed a bill that bans under certain circumstances the sale of the weapons and unfinished frames without serial numbers. It will be illegal to possess or receive an unfinished frame unless it has a serial number 180 days after day the law goes into effect.

Selling an unserialized firearm or gun kit will be considered a Class 4 felony, which could result in a fine and a prison sentence between one and three years. Anyone possessing or purchasing these weapons would be guilty of a Class A misdemeanor which could result in fines and a prison sentence less than one year.

The bill makes Illinois the first state in the Midwest to ban “ghost guns,” the Chicago Sun-Times reported.

In May, Illinois State Police worked on 28 cases involving ghost guns, Pritzker’s office said in a statement. Two teenagers were charged with the possession of “ghost guns” and individuals associated with multiple armed carjackings were arrested.

“We are seeing these unseralized guns being built in basements by those who should never have had access to such dangerous weapons and then used to commit heinous crimes, and it must be stopped to keep Illinoisans safe,” Pritzker said. 

Pritzker’s office noted that President Joe Biden’s administration has taken similar steps to address ghost guns” by requiring serialization and reclassifying the kits as firearms. In 2021, about 20,000 ghost guns were recovered during criminal investigations, a tenfold increase from 2016, the Justice Department said.

“These guns are weapons of choice for many criminals,” Biden said in a Rose Garden ceremony in April. “We are going to do everything we can to deprive them of that choice and, when we find them, put them in jail for a long, long time.”