South Carolina ? Freddie Grinnell wanted his children to do some old-fashioned trick-or-treating. After taking the family to a Halloween gathering, he drove to a neighborhood in this small city and shepherded his three eldest to a modest red house across the street from a graveyard.

The porch light was on. But police say the real nightmare was lurking inside.

After hearing the knock on his door, authorities say, a convicted felon fearing a robbery opened fire with an assault rifle from inside the house. At least 29 shots smashed through the front door and window frame, killing 12-year-old T.J. Darrisaw and wounding Grinnell and another son.

“This is by far one of the worst tragedies that I have had to personally experience,” police Chief Patty Patterson said Saturday. “It happened basically because kids were out doing what they would normally do on Halloween.”

Police said 22-year-old Quentin Patrick, a felon with multiple drug convictions, told them he feared the masked visitors were coming to rob him. Two of the boys, including the one who was killed, were wearing ghoulish masks as their Halloween disguises.

Patrick has been charged with murder, three counts of assault and battery with intent to kill, and one count of assault with intent to kill.