Updated

Illinois police have concluded that a 10-year-old boy who died after he was found hanging from a hook in an elementary school bathroom stall committed suicide.

Evanston Police Cmdr. Tom Guenther says investigators determined that fifth-grader Aquan Lewis was "unhappy" on Feb. 3 when he hanged himself at Oakton Elementary School.

At a news conference Tuesday, Guenther also said physical evidence — including the child's footprint on a toilet seat — indicates the boy hanged himself on the hook in the bathroom stall where he was found.

Earlier this month, the Cook County Medical Examiner's office ruled the boy's death was a suicide. But the boy's mother has said she didn't believe her son would kill himself.