A fellow student at SuccessTech Academy alternative school said Asa H. Coon, who was suspended for fighting two days earlier, had made threats in front of students and teachers last week.
"He's crazy. He threatened to blow up our school. He threatened to stab everybody," Doneisha LeVert said. "We didn't think nothing of it."
Armed with two revolvers, Coon fired eight shots and may have targeted teachers, Police Chief Michael McGrath said.
Math teacher David Kachadourian, who was treated at a hospital for a minor wound to the back of one shoulder, said Coon had been a student in a beginning algebra class he taught. But the 57-year-old teacher said he had not disciplined Coon and knew of no reason why Coon might target him.