What began as a routine response to a brush fire on northern Idaho’s Canfield Mountain turned deadly Sunday after firefighters reported someone shooting at them while they battled the flames.

Two firefighters were shot dead and a third wounded on an Idaho mountain when they were ambushed by a man who set the fire to lure them to the area, the local sheriff says.

New details are emerging about the 20-year-old suspect that police say started a brush fire and then began shooting at firefighters responding to it in an ambush-style attack. Police say he has no criminal record and likely used a shotgun before dying from a self-inflicted wound six hours after the shooting began.