[4] Mental health professionals are required to inform state authorities about patients who display violent, suicidal or threatening behavior, for inclusion in the Human Services database.

However, by January 2006, the backlog had increased and the State Police were taking as long as 50 days, in violation of the law, to issue or deny the FOID.

)[12][13] For private sales not at a gun show, the seller must also verify the buyer's FOID card with the state police, and receive a transfer approval number, either via a web site or with a phone call.

[16][17] On February 14, 2018, in a ruling on the case of People v. Brown that applies only to the defendant, a circuit court in Illinois found that the requirement to obtain a FOID in order to acquire or possess a firearm is unconstitutional.

[23][24] On April 27, 2021, White County Resident Judge T. Scott Webb once again ruled the FOID unconstitutional, saying, "A citizen in the State of Illinois is not born with a Second Amendment right.

[26] On July 18, 2023, in the case of Guns Save Life v. Kelly, a Sangamon County circuit court judge ruled that the state's FOID requirement is constitutional.

She wrote in her opinion, "There is ample historical evidence supporting the constitutionality of the FOID Act, and GSL's facial challenge fails as the historical record demonstrates that laws 'relevantly similar' to the FOID Act have been part of American legal history from the Founding Era to present day.