BOISE, Idaho -- Steve Groene, father of Dylan and Shasta, thanked jurors personally after they sentenced Joseph Duncan to death Wednesday afternoon. Groene even apologized to jurors for having to watch the horrific video Duncan made while he tortured and nearly killed Dylan in the Montana wilderness.

Groene's actions speak to the troubling and disgusting nature of Duncan's crimes-- and psyche-- that the jury had to endure for two weeks.

Prosecutors spent hours detailing Duncan's life as a sexual predator and killer. Duncan has now spent more than half of his life behind bars. His crimes began at the age of 17, when he raped a 14-year-old boy at gunpoint in Tacoma, Washington. Duncan was sentenced to 20 years in prison, but granted parole after serving 14 years.

Duncan appeared to get his life on track in the mid 90's, landing a job at Time Life Libraries in Seattle, where he met his girlfriend. But Duncan's rage eventually surfaced again. Detectives say he admits murdering two half-sisters in 1996 as an 'act of revenge' for his first prison sentence.

The following spring, Duncan has admitted driving to Southern California and murdering a 10-year-old boy. Duncan was never linked to the crime until his arrest in Coeur d'Alene in 2005.

After several short stints in jail for violating parole and not registering as a sex offender, Duncan was released without conditions in July of 2000. He moved to North Dakota and enrolled in college, where he majored in computer science.

Duncan lived under the radar until the summer of 2004, when he was accused of molesting a boy at a school playground in neighboring Minnesota. However, Duncan was not charged or arrested until March 2005.

On April 5th, 2005, a friend gave Duncan $15,000 so he could post bail. Duncan skipped down and criss-crossed the country on his way west.

Eventually, his travels took him to North Idaho, when in May 2005 he spotted young Dylan and Shasta playing outside their Wolf Lodge home.

Timeline of Duncan's criminal history:

* Jan. 1980: Duncan, then 17, arrested for raping a teenage boy at gunpoint in Tacoma, Washington. He's sentenced to 20 years in prison.

* Sept. 1994: Duncan freed from prison on parole.

* July 1996: Investigators say Duncan abducted and murdered two Seattle-area sisters, Carmen Cubias and Sammie Jo White.

* April 1997: Investigators say Duncan stole his girlfriend's car and drove to Southern California, where he kidnapped and killed 10-year-old Anthony Martinez.

* 1997-2000: Duncan jailed several times for failing to register as a sex offender.

* July 2000: Duncan released from prison unconditionally-- meaning he was not on parole or probation. Duncan moves to Fargo, ND and registers as a sex offender.

* August 2000: Duncan enrolls at North Dakota State University as a computer science major.

* July 2004: Duncan accused of molesting two boys at a Detroit Lakes, MN playground.

* March 2005: Duncan officially charged with child molestation.

* April 2005: A friend loans Duncan $15,000, allowing him to post bond.

* May 16, 2005: Bodies of Brenda Groene, Mark McKenzie and Slade Groene found at Wolf Lodge home.