BOISE, Idaho – In the end, killer pedophile Joseph Edward Duncan III couldn't – or wouldn't – offer a reason why he should live.

A jury didn't find one either, deliberating just three hours Wednesday before recommending a death sentence in the 2005 kidnapping, torture and murder of a 9-year-old boy.

The jurors' recommendation was binding on U.S. District Judge Edward Lodge, who thanked and dismissed them and then sentenced the longtime sex offender, who showed no reaction other than smiling.

Earlier, the former Fargo man acted as his own attorney but offered no response to prosecutors' closing argument detailing why he should die.

“I have no argument,” Duncan told the court.

Relatives of the victim, Dylan Groene, remained somber as the jury's decision was announced. Duncan murdered Dylan's mother, older brother and his mother's fiance. Duncan then kidnaped the boy and his younger sister, who was sexually abused along with her brother but survived.

“We're happy with the verdict, but it's a shame – this should have been limited to one death,” said Steven Groene, the father of the children. “He should have had the courage and the guts to kill himself before killing anyone else.”

Duncan took Dylan and the boy's then-8-year-old sister, Shasta, to a remote western Montana campsite where he raped, tortured and threatened them before shooting Dylan in the head and burning his body. Jurors viewed horrifying video Duncan made of him sexually abusing, torturing and hanging Dylan until the boy lost consciousness.

“This defendant is dangerous. He is a predator who takes pride in his work,” prosecutor Traci Whelan told the jury. “He earned this day.”

With an eye toward kidnapping the two children, Duncan stalked their family. In 2005 he entered their Coeur d'Alene-area home and used a hammer to fatally bludgeon their 13-year-old brother, Slade Groene, his mother, Brenda Groene, and her fiance, Mark McKenzie.

Duncan was arrested and Shasta rescued weeks after the kidnappings when a waitress at a Coeur d'Alene restaurant called police after recognizing the two as they ate.

Duncan pleaded guilty in December to 10 federal charges involving the kidnappings and the murder of Dylan. He previously pleaded guilty to the other three murders in state court, where he also could be sentenced to death.

The federal jury had a choice of recommending a death sentence or life in prison without parole.

In closing arguments, Whelan reminded the jury of Duncan's lifelong “pattern of violence,” including a conviction for raping a boy at gunpoint in 1980. Duncan has told investigators he killed two half-sisters from Seattle in 1996, and he is charged with killing a young boy in Riverside County, Calif., in 1997.

Duncan may now be brought to Riverside County to stand trial in the death of 10-year-old Anthony Martinez.

Darlene Torres, Brenda Groene's mother, said she is glad the federal case is over.

“Justice has been served,” Torres said. “It's been very painful.”

She said that when she saw Duncan in court, “I seen nothing but an evil, empty, cold-hearted shell.”