Miami - A 20-year-old with a history of mental illness and carrying nearly 500 rounds of ammunition was behind a US elementary school shooting in the state of Georgia, police said on Wednesday.
Michael Brandon Hill entered the Ronald E McNair Discovery Learning Academy near Atlanta on Tuesday armed with an AK 47-style assault rifle, then took one or two staff members hostage before surrendering, police said.
No one was wounded in the incident, which began around noon.
Hill reportedly forced one hostage to call a local news channel, then also allowed her to call 911 asking for his parole officer to intercede on his behalf.
Special police teams surrounded the facility, organised its evacuation and Hill "started to fire from inside the school at our officers," DeKalb County Police Chief Cedric Alexander told a press conference in Atlanta on Wednesday.
Police returned fire, but Alexander did not comment on how they convinced the young man to surrender.
"Before going to the school, suspect Michael Brandon Hill took a photo of himself with an AK 47-style rifle," Alexander said on Wednesday.
According to local media, Hill has been charged previously for carrying a weapon without a permit and making terror threats.
The public defender's office, which will represent Hill, reiterated on Wednesday that he has mental issues.
"Mr Hill is being represented by members of our mental health division and he has decided to waive his first appearance hearing," the office said in a statement.
Hill will appear at a preliminary hearing on 5 September.
The incident comes eight months after the US school massacre at Sandy Hook Elementary in Newtown, Connecticut, when a young gunman killed 20 small children and six adults in a shooting spree.