Idaho killer Duncan pleads guilty to 1997 Calif. murder.

Idaho killer Duncan pleads guilty to 1997 Calif. murder.
INDIO, Calif. (AP) - A man convicted in a horrific Idaho murder case pleaded guilty Tuesday to torturing and killing a 10-year-old-boy in Southern California in 1997.

Joseph Edward Duncan III, 48, entered the plea in Riverside County Superior Court in exchange for an agreement to be sentenced to life in prison without the possibility of parole and to waive his right to an appeal.

Duncan was charged with killing and torturing 10-year-old Anthony Martinez, who was abducted in 1997 as he played with his brother near their Beaumont home. Martinez's nude and battered body was found two weeks later in the desert east of Los Angeles.

Duncan confessed after he was arrested in Idaho for the 2005 killings of two boys, their mother and her fiance, and the abduction of the boys' sister. He received three federal death sentences and multiple life terms.

Riverside County prosecutors had sought the death penalty for Duncan but agreed to the plea after consulting with Martinez's relatives, who wanted closure on the case, said District Attorney Paul Zellerbach.

"The federal system will kill him long before the state of California would have seriously considered it," Zellerbach said. "In California, we have now guaranteed that he will never get released regardless of what happens in any other jurisdiction, in any other state."

A call to Duncan's attorney Scott O'Meara was not immediately returned.

Duncan was sentenced to death in 2008 for the kidnapping, torture and murder of 9-year old Dylan Groene of Coeur d'Alene, Idaho. He abducted the boy and his 8-year-old sister Shasta after killing their older brother, mother and her fiance with a hammer at the family's home in 2005.

He took the children to a remote western Montana campsite where he raped, tortured and threatened them before shooting Dylan in the head and burning his body.

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

Duncan previously had been sentenced to 20 years in prison for sexually assaulting a 14-year old boy in Tacoma, Wash., in 1980. He was paroled in 1994 but was returned to prison in 1997 after breaking the conditions. He was released in 2000 and lived in Fargo, N.D., before his arrest in the grisly Idaho murders.

Riverside authorities spent years searching for a suspect in Martinez's killing. They pursued more than 15,000 leads and were only able to link Duncan to the crime after his Idaho arrest.

Duncan is scheduled to be sentenced on April 5.

An FBI agent told a federal jury in 2008 that shortly after his arrest in the Idaho case, Duncan confessed to killing Martinez, as well as half-sisters Sammiejo White, 11, and Carmen Cubias, 9, near Seattle in 1996. Dan Donohoe, a spokesman for the King County Prosecutor's Office in Seattle, said those killings remain under investigation.