BOISE (AP) — The U.S. Supreme Court won't consider whether Joseph Duncan, convicted of kidnapping, torturing and murdering members of a Kootenai County family, was competent when he waived his appeal.

The high court rejected the petition from Joseph Edward Duncan III on Monday. Now U.S. District Judge Edward Lodge in Idaho must hold a hearing to determine if Duncan was competent when he decided to waive his right to an appeal in the 2008 death penalty case. If Duncan is found to be incompetent in the matter of waiving his right to an appeal, Lodge must hold an additional hearing to see if he was competent when he represented himself during his sentencing hearing.

Lodge sentenced Duncan to die for kidnapping, torturing and murdering a 9-year-old Coeur d'Alene boy in 2005. Prosecutors said Duncan snatched Dylan Groene and his 8-year-old sister from their home after killing their older brother, mother and mother's fiance. Duncan kept the children at a remote Montana campsite for weeks before killing Dylan and returning with Dylan's sister to Coeur d'Alene, where he was arrested.

Duncan has also been sentenced to two life terms in California state court for torturing and killing 10-year-old Anthony Martinez in 1997. Duncan abducted Martinez as the child played near his Beaumont, Calif., home. The boy's body was later found in the desert.

An FBI agent told the federal jury in the Idaho case that shortly after his arrest, Duncan acknowledged killing Anthony. Agent Mike Sotka also said Duncan confessed to killing of half-sisters Sammiejo White, 11, and Carmen Cubias, 9, near Seattle in 1996.

At the sentencing hearing in Idaho, Duncan decided to represent himself even though the court had provided him with three defense attorneys. The court-appointed attorneys were ordered to help Duncan when he asked, but otherwise allow him to present his own defense.

The attorneys objected, telling the court that they suspected Duncan wasn't competent to represent himself, but Lodge rejected that challenge and decided not to hold a hearing on the matter. Instead, he had Duncan examined by a local psychologist who found that while Duncan's thoughts were "somewhat unusual," he wasn't delusional and that he'd waived his right to an attorney knowingly and voluntarily.

Duncan's attorneys, meanwhile, contended that experts they contacted found that Duncan suffered from delusional beliefs, paranoia, grandiosity and psychotic breaks from reality.

Lodge decided to let Duncan represent himself, and Duncan waived his right to an appeal after he was sentenced to death.

Last summer, the 9th U.S. Court of Appeals said that Lodge should have held a hearing on Duncan's competency before making any decision on the matter. The appellate court reversed and remanded the case, ordering Lodge to hold a retrospective hearing to see whether Duncan was competent to waive his right to an appeal.