One of the guns recovered was a military-style .223-caliber semiautomatic Bushmaster rifle with flash suppression, the same make and caliber weapon used in the elementary school massacre in Newtown, Conn., Pickering said.

The chief said police believe the firefighters were hit with shots from the rifle given the distance but the investigation was incomplete.

The two- to three-page typewritten note left by Spengler didn't give a motive for the shootings, Pickering said. He declined to divulge the note's full content or say where it was found, but read one line from it: "I still have to get ready to see how much of the neighborhood I can burn down, and do what I like doing best, killing people."