Zella Strickland

Joseph Duncan in federal court.

BOISE - Testimony in the death penalty hearing of confessed child killer Joseph Duncan Tuesday focused on the murders of two half-sisters in the Seattle-area in 1996.

Duncan had confessed killing the two Seattle sisters, 11-year-old Sammy Jo White and 9-year old Carmen Cubias. The two were last seen alive at a Taco Time near the motel where their family was living.  In a taped confession to a special agent with the FBI, Duncan called the murders his "first sheer, unadulterated revenge against society."

On Tuesday, Bothell, Wash., Police Det. Dennis Nizzi took the stand first, describing human bones found in February 1998. Nizzi told the court the bones were confirmed as the two missing girls, Carmen Cubias and Sammie Jo White, and that he had to notify their mother.

Joseph Duncan questioned Nizzi, asking, "Was Joseph Edward Duncan ever a suspect or person of interest in that case prior to July of 2005?"

Nizzi responded that Duncan was at the bottom of a list of sex offenders, but they didn't get that far down the list because of other leads they'd been following up on.

Later in the morning, Duncan's ex-girlfriend took the witness stand. Dee Ellis says she met Duncan while they both worked at Time Life Libraries in 1996 and 1997. Ellis' testimony gave no specific details on their relationship. She identified the location of her home, which was just a few blocks from the spot where the girls were abducted.

Duncan smiled when Ellis took the stand and seemed to be look longingly at her. Ellis did not look at Duncan.

Prosecutors also called Joseph Ruan, who was Duncan's roommate from April of 1996 to April of 1997. Ruan had flyers of the missing girls because he and another friend had been helping search the neighborhood. Ruan told jurors he and Duncan were watching TV when a report about the girls came on. Ruan says Duncan commented that Cubias and White looked like "whores" and "gangbangers".

Duncan cross-examined Ruan, asking a bizarre line of questioning: "I moved in with you on April 1st 1996? I was living with you when those girls disappeared? I made those comments while watching TV while we were living together? So, if I wasn't living with you at the time, I couldn't have made those comments?"

Monday testimony

On Monday, FBI Agent Mike Sotka told jurors Duncan said he hit both of the two girls over the head with a crowbar after walking them into the woods. Duncan often lured his child victims into secluded areas by telling the kids he was looking for his lost cat, Sotka testified.

Prosecutors also called family members of Anthony Martinez to testify. Martinez was abducted and murdered in Riverside, California in 1997.

The boy's brother, now 17, told jurors he remembered Duncan telling him, Martinez - his half brother - and some other boys that he would give each of them a dollar if they helped him find his cat. Medina says Duncan then grabbed Martinez, put a knife to his head, put him in the car and drove off. It was the last time he ever saw his brother alive.

Attorneys for the confessed child killer tried to persuade the judge that testimony related to past crimes are not relevant given the fact that Duncan will spend the rest of his life in prison-- at the very least. The judge refused and allowed testimony to resume.

A jury determined on Friday that Duncan is eligible for the death penalty for the rape and murder of Dylan Groene in 2005. Jurors will now rule whether he should be executed or spend life in prison.