Investigators recently named the victims injured and killed in a July 15 shooting on Kirkland Road by a Riverdale man, who reported his actions to deputies.

Joseph Matthew Miller, 17, of Covington, died on the scene before first responders arrived after he was allegedly shot in the chest by Delaney Douglas Robinson, 22, according to Newton County Sheriff's Office investigator Sgt. Sonny Goodson.

Robinson reportedly became embroiled in an argument with Miller and the two other victims - an 18-year-old and 19-year-old, both of Covington - and pulled out a handgun from his waistband.

According to Goodson, Robinson shot each victim once at close range with the .45 caliber handgun on the back porch of the house before going across the street to a business to call 911. Deputies found Robinson where he made the call and arrested him without resistance.

One survivor had a bullet enter his side and remain visibly lodged in his stomach, while the other man was shot through the hip with an exit wound in the buttocks. Both surviving victims were treated and released from Atlanta Medical Center.

The mother of one of the victims said a group of friends had gathered for a mutual friend's birthday, but that Robinson was the least familiar with the group.

The cause of the argument and the relationship of the shooter to the victims are still under investigation, Goodson said, but no drugs or alcohol appeared to be involved and the victims reportedly did not have weapons during the incident.

Goodson described the case as relatively open and shut - with the alleged shooter in custody, a confession, the alleged murder weapon taken into evidence, corroborating witness statements and shell casings recovered from the crime scene. He added seeing a young person killed was never easy for investigators.

"It's terrible," said Goodson, describing it as one of the worst parts of his job.

The surviving victim's mother said Miller, who split his time between Georgia and Florida, had just gone to church two days earlier.

"He had just turned his life over to God," she said.

Before he died, she said he gripped the hand of one of the residents and told them he'd see them on the other side.

A worker at the Golden Pantry store on Salem Road said she remembered Miller as a polite young man who would come in regularly and joke around with the employees. He never caused any trouble, she said, unlike other teenagers. She shook her head at the suddenness of it all; she had spoken to Miller only a day or two before he was killed.

Miller's funeral is scheduled this weekend in Florida, according to the surviving victim's mother.