COLUMBIA, S.C. - An ex-convict charged with killing a South Carolina child who knocked on his door on Halloween night is now facing a federal weapons charge, prosecutors said Wednesday.

A federal grand jury indicted Quentin Lamar Patrick, 22, Wednesday on one count of being a felon in possession of firearms and ammunition, a crime punishable by up to life in prison and a $250,000 fine, U.S. Attorney Walt Wilkins said.

The charge is connected to two guns found in Patrick's home the night of Oct. 31. That night, police say Patrick, who has multiple drug convictions, emptied an AK-47 into his front door, walls and windows when he heard a knock at his door.

T.J. Darrisaw, 12, was killed in the rain of at least 29 bullets. His 9-year-old brother, Ahmadre Darrisaw, and their father, Freddie Grinnell, were injured but were released after being treated at a hospital. Another sibling with them wasn't hurt.

The family attended a Halloween celebration in downtown Sumter, 45 miles east of Columbia, then stopped at Patrick's house because the porch light was on, police said.

Patrick, who told police he had been robbed and shot in the past year, told investigators he thought he was being robbed when he sprayed the front of the house with bullets. He has been charged with murder, three counts of assault and battery with intent to kill, and one count of assault with intent to kill.

Police found a handgun that was not used in the shootout, as well as ammunition for both guns in the home when they arrested Patrick.

Federal prosecutors said Wednesday they have been working with Sumter County prosecutors and will transfer Patrick to federal custody before a hearing on the weapons charge next month.

An attorney representing Patrick on the murder charge did not immediately return a phone message seeking comment. Patrick may have a different attorney assigned to represent him on the weapons charge at his federal arraignment, Assistant U.S. Attorney Kevin McDonald said.