Death Penalty Sought For Duncan

Convicted Sex Offender Accused Of Idaho Slayings, Child Kidnappings

(CBS/AP)  Duncan, 42, is charged with killing Shasta and Dylan's mother, Brenda Groene, 40; her boyfriend Mark McKenzie, 37; and her 13-year-old son Slade.

Authorities contend he watched their home along Interstate 90 for days, then entered the night of May 15-16, tied up the three victims — the basis for the three kidnapping charges — and beat them to death with a hammer.

Court documents allege he then held Shasta and her brother for weeks at a campsite in Montana where he molested them and eventually killed the little boy.

Federal charges are expected later in the crimes against the younger children, since they were taken across a state line. Under federal law, a kidnapping that results in a death is punishable by death.

Duncan also is being investigated in the killings of a 10-year-old boy in California in 1997 and three children — ages 7, 9 and 11 — in Washington state in 1996.

Duncan was sentenced to 20 years in prison in Washington for sexually assaulting a 14-year-old Tacoma boy in 1980.

Authorities said he was paroled in 1994 and moved into a halfway house.

He was returned to prison in 1997 after testing positive for marijuana use, then was released in 2000. At the time of his July arrest, Duncan was a fugitive charged with molesting a 6-year-old boy in Minnesota.