The agency announced Monday that is examining whether the court provides due process to all children appearing for delinquency hearings.
Another youth is suspected of pulling the trigger, family cooperating with police.
Lawsuit claims too many kids behind bars illegally.
Belleville police say a 7-year-old boy is one of two juveniles arrested in connection with a series of break-ins of vehicles last weekend.
Other states are looking to Missouri for guidance
Young victim later developed cocaine addiction and had to be institutionalized.