SUMTER, S.C. (AP) - A 12-year-old boy was shot to death through a front door while trick-or-treating with his family, shocking residents of a South Carolina neighborhood where most people know each other well.

"I just hate it that that little kid got killed. It used to be the quietest place. I knew everybody and everybody knew me," Vivian Johnson, 81, said Saturday.

She has lived for decades two doors from the house where the boy was killed and his father and brother injured Friday night, but she said she does not know the people who live there now.

Police offered no motive and said it did not appear the family knew the people in the house, which is off a busy, two-lane road in Sumter, a city of about 40,000 people 45 miles east of Columbia. On Saturday, shattered glass still covered the front stoop and about 20 bullet holes peppered the front door and a front-window casement.

A 22-year-old man was charged with murder but it wasn't clear how - or if - he was connected to the family.

"Most times you can find an explanation no matter how strange or twisted it is. Right now we have no explanation," said Mayor Joseph T. McElveen. "Sumter's certainly not a violent town but we're not isolated to having tragedies like this happen. It doesn't make it any better."

Police said the boy, his parents and three other siblings were returning from a city-sponsored event downtown where about 4,000 costumed children had celebrated Halloween when they stopped to collect candy at a home with a porch light on. The father and children went to the door while the mother stayed in the car nearby.

As the family waited, they thought they heard fireworks. The father and two boys were hit by gunfire from inside the house. The 12-year-old died at a hospital, Coroner Verna Moore said. His father and brother were taken to a hospital with non-life-threatening injuries. The other two children were not hurt. Authorities have not identified the family.

Quentin Patrick, 22, has been charged with murder and three counts of assault and battery with intent to kill. The home where the shooting happened was not listed as his address and it wasn't clear why he was there.

Sumter Police Chief Patty Patterson said there were other people inside during the shooting, but she didn't expect them to be charged.

There was no answer Saturday morning at the mobile home police listed as Patrick's address, although neighbor Larry Sigler said he thought Patrick's mother lived there.

Sigler said Patrick didn't seem like someone prone to violence.

County Councilman Charles Edens said he lives just a few blocks away from where the shooting happened and passed the flashing lights of police cars on his way back from trick-or-treating with his 13-year-old daughter, who was upset at the news.

"It's going to put a dampening on Halloween," Eden said. "I would think twice about going to a door that we don't know who lives behind."