RICHMOND, Ind. (AP) — Police say a 14-year-old Indiana boy’s mother was the 911 caller who warned authorities before the teenager shot his way into a middle school and exchanged gunfire with officers.

State Police said Friday that the mother warned of “imminent danger” before Thursday morning’s shooting at Dennis Intermediate School in Richmond.

Her tip meant the school was on lockdown when the boy shot out glass in a locked door, entered the school and exchanged shots inside with pursuing police officers before apparently killing himself.

Police also announced that preliminary autopsy results show the teen died from a single, self-inflicted gunshot wound.

Richmond Police Chief Jim Branum tells the Palladium-Item the boy was carrying a pistol and a rifle when he entered the school. No one else was injured.

The Indiana State Police have released the cause and manner of death and the identity of the teenager responsible.

Preliminary autopsy results indicate that Brandon Clegg, 14 of Richmond, died of a self-inflicted gunshot wound.  The location of the wound has not been released at this time.