The jury took three hours before deciding Duncan should be executed for the torture slaying of Dylan Groene, who he kidnapped along with his sister from his Idaho home, KTRV-TV in Boise reported.

Duncan may now be sent to Southern California to stand trial for the 1997 kidnapping and killing of Anthony Martinez, 10.

Authorities said Duncan killed Dylan's mother, older brother and his mother's fiance to kidnap him and his younger sister.

Duncan took the two children to a Montana campsite where he raped and tortured them before shooting Dylan in the head and burning his body. Dylan's sister was rescued weeks later when a waitress at a restaurant in Coeur d'Alene called police after recognizing the two.