Police say it was 9-year-old Stephen Lanese who accidentally shot and killed his identical twin brother Christian when he was playing with his father's hunting rifle in October.

But now, police have charged the father, 66-year-old Michael Lanese of Upper St. Clair, in the boy's death, saying that Mr. Lanese was "grossly negligent" the night that Christian was shot. He told police he was in the living room reading a book and thought the two were playing video games when he heard the gun go off.

Mr. Lanese was arraigned Saturday morning on charges of involuntary manslaughter and endangering the welfare of a child.

On Oct. 18, the day that Christian was killed, police said Mr. Lanese had tried to sell three of his guns a flea market. When they didn't sell, he returned home to have the boys clean the guns and take them to the master bedroom. Stephen told police that they both started playing with one of the guns, a .348 caliber Winchester rifle, loading and unloading using a lever action. Stephen pulled the trigger and the gun discharged, striking his brother in the back of the head and killing him instantly.

When police arrived on scene, they said they found the rifle on the bed and three knives "in plain view" on top of a bureau. Though Mr. Lanese initially said he only had one gun in the house, he later revealed that he had moved the other two guns from the master bedroom before police arrived. He also said the boys must have obtained the ammunition from a locked cabinet in the basement, but police found ammunition for another gun, a .22 caliber, in a nearby desk drawer.

But that night in October was just one of many times police say the boys had access to guns. In an affidavit, Allegheny County homicide detectives painted a picture of Mr. Lanese as a neglectful father who left his two young sons home alone, sometimes unfed, and allowed them to play with guns, knives and swords unsupervised.

Neighbors told police that the boys would sometimes complain that they had been left home alone and were hungry. On more than one occasion, they observed them playing dangerous games outside of their house on Eton Road, throwing a hatchet, swinging around a Samurai sword and smashing a computer monitor with a baseball bat while they stepped on the glass with their bare feet.

A nurse at Streams Elementary School, where the boys attended third grade, told police that they often came to school with burns and bruises that the boys reported were the result of playing with a pellet gun, prompting the nurse to report the injuries to the Office of Children, Youth and Families.

Mr. Lanese's ex-wife, Truc Phan Lanese, the boys' mother, also told police that the utilities had been shut off in the month before Christian's death due to non-payment, and his 17-year-old daughter, Amy, said she regularly saw guns and ammunition lying out.

Detective Terry Hediger say that the incidents indicate a "course of conduct."

"It's an ongoing way of conducting yourself, it's not just a one-time occurrence," he said.

Shortly after the incident, Mr. Lanese told the Post-Gazette that he had done "nothing negligent," and said that he would not be charged. But the investigation was revived in mid-January, when the district attorney's office asked county police to look into the case.

His preliminary hearing is scheduled for Friday.