Richard L. Moore Jr. doesn't know which of his 22 guns, locked in a bedroom and unloaded, killed 15-year-old Michael D. Brooks Jr. after a sleepover Saturday morning. His collection included black powder pistols, Western revolvers and military-style firearms, he said Monday.

It was a handgun, is all police will say about the weapon that killed Michael. The shooter was an 11-year-old boy, police said, and Michael was struck at least once in the head in what appeared to be an accident inside an apartment in Cherry Hill.

""There's definitely an issue of the weapons being properly stored," police spokesman Anthony Guglielmi said.

The boy who pulled the trigger will not face charges, the spokesman said. But he did say detectives are working with the state's attorney to determine if charges are warranted against anyone else connected to the case.

Moore is a retired correctional officer who worked at the Patuxent Institution in Jessup for 22 years. He said he was in the Marine Corps and the Army, and was in charge of small arms during his final stint in the Marines.

His gun collection was locked away in an upstairs room, Moore said, but there was a spare key pushed back on the top shelf of the hall closet. Moore said he is not sure if the spare key was used to enter the room by the three boys at the sleepover.

"I didn't think he could even reach that key," Moore said of the 11-year-old, who has not been named by police because of his age, and because he has not been charged. Police have not said which child first got hold of the weapon.

Michael spent the night with his half-brother Jeremiah Wenth, 12, and the 11-year-old at Moore's home in the 2400 block of Seamon Ave. Friday night, Moore said. About 11 a.m. Saturday, he said, the boys were left in his apartment with his 85-year-old aunt and 21-year-old nephew. Moore went off to look at a home he was considering moving into, he said.

About fifteen minutes later he received a call from the 11-year-old, who he said was "screaming hysterically." The boy said Michael had been shot. Moore said he told him to call 911, and sped home.

Michael's mother, Sheila Horn, said her son was a well-mannered 15-year-old who would have entered the 10th grade at Lansdowne High School this fall and planned to try out for football.

"He was a great kid — quiet, very well-mannered," she said. He was in JROTC last year, she said. Michael had a twin sister named Vanessa, his mother said, and was excited about getting his permit and learning how to drive.

Michael lived with his grandmother and extended family a few miles away in Baltimore County, in the 2800 block of Oak Grove Ave. But Michael was staying for part of the summer in the complex where he was killed, she said.

"He was like a brother to me," said a cousin, Christina Horn, 13. Michael lived with her and her parents at the home of their grandmother, Jean Horn, and they spent a lot of time playing and learning sports together, she said.

Jeremiah and the 11-year-old had been friends for several years, Moore said, but Friday was the first time he had met Michael. The boys had been forbidden from going into Moore's locked bedroom, he said.

Police confiscated the gun collection, Moore said, and so he never found out which gun had been fired. Everything Moore knows about what happened during those fateful 15 minutes, he said, is what the police have told him.

"All they said was the gun was mishandled and a young man is dead and, as far as I know, it's still an ongoing investigation," said Moore, whose last job before retirement was with a private security firm. Moore said that there was only one gun in the bedroom that was not locked up, but it was in a case and it was unloaded.

He considered getting a gun safe, Moore said, but because his residency was temporary and he was about to move, he decided against it. "Bringing a safe into a house," he added, "is like signaling you have something to steal."

Viewings for Michael D. Brooks Jr. are scheduled for 7 p.m. to 9 p.m. Wednesday, and Thursday from 3 p.m. to 5 p.m. and 7 p.m. to 9 p.m. at Bailey Funeral Home, 4023 Annapolis Road, Halethorpe. The funeral service will be held at 10 a.m. Friday at Christ United Methodist Church, 2833 Florida Ave. in Baltimore.

steve.kilar@baltsun.com

Baltimore Sun reporter Justin Fenton contributed to this article.