DECATUR, Georgia (AP) — Police say the suspect in Tuesday's U.S. school shooting had nearly 500 rounds of ammunition.

DeKalb County Police Detective Ray Davis says police believe that Michael Brandon Hill got the AK 47-style rifle from an acquaintance. But Davis told a news conference Wednesday that it's not clear if Hill stole the gun or borrowed it.

No one was injured at the Georgia school, but police say the suspect exchanged gunfire with officers. They say he also fired once into the floor of the school office.

Witnesses have said Hill mentioned being off his medication.