Only the Chicago and Rockford police departments report firearm-related domestic violence homicides to the FBI.

The Illinois State Police says the relationship of a homicide victim to the offender is considered supplementary data that is not required to be reported.

Twenty-six of the 38 homicide victims were either a wife or girlfriend of the offender. Thirty-three of the deaths happened in Chicago.

Federal and Illinois state law prohibit those convicted of a domestic-violence charge from owning a firearm ever again.

Illinois law also requires gun owners with a restraining order against them to surrender their firearms to law enforcement.