police were today detonating a huge explosives haul at the home of a man accused of shooting dead eight people, including a four-year-boy.
Security guard Christopher Speight (39) gave himself up after a 18-hour manhunt following the killings at a house in rural Virginia.
The victims were four adults, three teenagers and the boy.
Police said Speight knew all the victims and had lived at the home where the massacre occurred, but they would not reveal the victims' relationships or discuss a motive.
By early today, bomb squads had detonated seven explosives and the blasting was expected to continue throughout the day.
Speight was unarmed when he surrendered at the house. He was wearing a bulletproof vest over a black fleece jacket, camouflage trousers and mud-caked boots.
"This is a horrific tragedy," state police spokeswoman Corinne Geller said. "It's definitely one of the worst mass killings in Virginia, probably since the Virginia Tech tragedy (in April 2007)."
Speight co-owned and lived in the two-storey home where some of the bodies were found.
The house had a big patio, where there was furniture, a children's bicycle and a plastic basketball hoop. The garden was landscaped and well-looked after.
Neighbour Monte Mays said Speight's mother signed over the house to Speight and his sister in 2006, shortly before she died of brain cancer.
Mr Mays said Speight was a good neighbour. They waved as they passed each other on the road and sent their dogs out to play with one another.
Speight had long been a gun enthusiast and enjoyed target shooting at a range on his property, Mr Mays said.
But the shooting recently became a daily occurrence, with Speight firing what Mr Mays said were high-powered rifles.
"Then we noticed he was doing it at night-time", he said, and the gunfire started going deeper into the woods.
Mr Mays said the community was devastated and wondering what triggered the killings.
"The only one who's going to know now is Chris," he said.
David Anderson, co-owner of the Sunshine Market grocery store in Lynchburg, where Speight sometimes provided security, said Speight was worried that his sister and brother-in-law wanted to kick him out of the house. Speight never wanted to talk about it, but "constantly paced the floor", Mr Anderson said. "I thought he was going to wear a trench in it."
Police were alerted to the bloodbath on Tuesday when they found the wounded man on the side of a road.