Alabama police said Monday they killed Jimmy Lee Dykes, who kidnapped a boy and held him hostage in a bunker.
His five-year-old hostage, Ethan, was said to be unharmed, reported the Associated Press.
Authorities remained tight-lipped about the raid Monday afternoon that led to Ethan's release, but on Tuesday ABC News reported that the FBI was able to get a camera into the bunker to monitor Dykes' movements.
The killing of Dykes, 65, ended a seven-day stand-off that captured national attention.
Dykes had kidnapped the boy from a school bus in Midland City, Ala. after killing the school bus driver.
He took the child about three miles away to a bunker in the hamlet, Newton, Ala. where police had been negotiating the boy's release.
BBC reported that local residents said they heard a boom and then gunshots on Monday afternoon.
The boy was believed to be in imminent danger.
"Within the past 24 hours, negotiations deteriorated, and Mr Dykes was observed holding a gun," said FBI spokesman, Steve Richardson, in a news conference after the rescue, reported the Guardian.
"Believing the child was in imminent danger, agents entered the bunker and rescued the child."
The rescue attempt began at 3:12 pm.
Hostage-taker Dykes was a Vietnam veteran and has been described as an anti-government "survivalist," with a history of violence.
Ethan is said to turn 6 on Wednesday.