The suspect was brought to state police headquarters in Appomattox
Police say they have found a "multitude" of explosives at a home in the US state of Virginia where eight people were shot on Tuesday.
Bomb experts searched the rural property after the suspect in the shootings gave himself up after an all-night manhunt.
Police say they are exploding the devices hidden both in and outside the suspect's house.
Medical examiners will try to identify the victims once the area is secured.
The suspect is reported to have been personally acquainted with the victims.
The man, named as Christopher Speight, 39, turned himself in at about 0710 (1210 GMT) after an all-night stand-off with police, who had surrounded woodland just outside the town of Appomattox.
The local sheriff said Mr Speight was wearing a bullet-proof vest when he surrendered, but was not armed and did not need any medical attention.
Sheriff O Wilson Staples said the suspect had shot at a helicopter which had been called to the scene, hitting its fuel tanks and forcing it to land.
Police are still searching for the high-powered rifle he is believed to have used. The sheriff said that based on the weapons found in the house, it was likely the suspect had been trained in the use of firearms.
Mr Speight has been taken to Appomattox regional jail, pending charges.
A spokesman for Virginia's governor said the suspect was being debriefed and was being very co-operative, although a motive for the shooting was still being investigated.
News of the shootings broke on Tuesday afternoon and everyday life in the area was paralysed, with local schools closing down as police hunted for the gunman.
The authorities were first alerted when they received a call about an injured person lying in the middle of a road.
When a deputy arrived at the scene, he heard gunfire and called for back-up.
The injured man was taken to hospital where he died of his wounds.
Police from across the state were brought into the densely wooded area, which is about 100 miles (160km) south-west of Virginia's capital, Richmond.
Police dogs and a National Guard helicopter with thermal imaging equipment were used to search the woods.
Mr Speight is the co-owner of the house in Snapps Mill Road, where the first reported victim was found.
He also owns a large tract of land next to the house.
The Washington Post quoted local officials as saying two of the dead were believed to be his wife and son.
Police found three bodies inside the house and another four outside. The eighth victim was the man found injured in the street.
County Administrator Aileen Ferguson said it was one of the worst mass killings in Virginia's history, "probably the worst since the Virginia Tech killings in 2007", when a student shot 32 people .
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