When serial killer Joseph Duncan was housed at the Ada County Jail for his 2008 death penalty trial, staff say he was a model prisoner.

"He knew the rules; he did not violate the rules," said Assistant U.S. Attorney Justin Whatcott. "He knew when to ask for things when needed."

Duncan spent most of his time on a court-issued laptop, preparing for his hearing.

"He exhibited nothing to lead them to believe he had any mental issues," Whatcott said during his opening statement at Duncan's competency hearing Tuesday morning.

Four staff members at the jail in Boise are expected to testify at the hearing at the federal courthouse in Downtown Boise. The hearing is a retroactive one aimed at determining whether the five-time convicted killer was competent in November 2008 when he waived his right to appeal his three death sentences, imposed by a federal jury in Boise for the 2005 kidnapping, rape and murder of a 9-year-old North Idaho boy.

Duncan arrived at the Ada County Jail last Thursday, where he's being housed in solitary confinement. He appeared in court Tuesday in yellow Ada County Jail pants, t-shirt and long-sleeved shirt, with his hair short and his face showing slight stubble.

The 9th Circuit Court of Appeals ordered the hearing before U.S. District Judge Edward Lodge, which is expected to last about six weeks and could include legal wrangling about how to handle testimony of Duncan's previous attorneys without violating attorney client privilege.

Michael Burt, a court appointed anti-death penalty lawyer from San Francisco, said he wants to question the lawyers through video for Lodge or in a courtroom closed to journalists and the rest of the public.

Burt said the lawyers don't want their interactions with Duncan detailed in public because it could affect trust with future clients.

"Their concern is that their other clients will learn about this," Burt said.

Those lawyers include famed defense lawyer Judy Clarke, who is widely considered the country's top anti-death penalty lawyer.

The court has not yet decided how exactly their testimony will be taken.

Burt said Duncan's previous defense team will discuss why they waited so long to question Duncan's competency. Burt said he'll also present mental assessments of Duncan dating back to when he was 17 and will show that the longtime sex offender "has a long standing delusional belief system that has originated before this case began and has continued up until the present day."

Burt said even one of the government's experts is expected to testify that Duncan has a personality disorder.

But prosecutors say their case includes the only true evidence of Duncan's competency: audio recordings of 24 hours of interviews Duncan did with FBI Special Agents Mike and Gail Gneckow after his death penalty trial in 2008.

"We believe this is the most relevant evidence on the issue of the defendant's state of mind when he waived appeal," Whatcott said. "Frankly, it is the only evidence the court will hear that is specific to that very time frame."

Whatcott said Duncan spoke specifically about his decision to waive appeal and to act as his own lawyer, as well as "his beliefs about the criminal justice system and the death penalty."

Duncan gave similar interviews to authorities in Riverside County, where he pleaded guilty in 2011 to the 1997 murder of a 10-year-old boy. His reasoning has always been consistent, Whatcott said.

But Burt said Duncan's defense lawyers will refute those statements. They spent much more time with him and saw much more of him than when "Mr. Duncan was putting on his best face in interviews with law enforcement."

Expected to testify is John Adams, head of the Kootenai County Public Defender's Office and Duncan's main lawyer during his state proceedings. Duncan pleaded guilty in October 2006 to the May 2005 kidnapping and murders Brenda Groene, Mark McKenzie and Slade Groene.

Adams interacted with him again while he was decided whether to appeal, Burt said, and will talk about the stark changes in his mental state.

"He consistently and persistently expressed delusional thoughts," Burt said. "One was a belief system that centered around an epiphany that Mr. Duncan had. His belief was and it still does require that he does not participate in the criminal justice system, that he allow whatever's going to happen to him happen without any participation by him....It's a belief system that long preceded events in November 2008." The "epiphany" described by Duncan involves lessons he says he learned from Shasta Groene, then 8 years old, after kidnapping her.

Duncan said he had the epiphany just as he was about to murder Shasta by striking her in the head with a rock, which is how he killed two young girls in the Seattle area in 1996, and how he killed the boy in Riverside County.

If Lodge decides Duncan wasn't competent when he waived his appeal, he'll then have to decide if Duncan was competent to serve as his own lawyer. Burt said he'll argue that he wasn't, but Whatcott previewed a plethora of evidence to the contrary, including transcripts from the death penalty hearing that he said will show Duncan knew what he was doing throughout the trial.

Gneckow, who was the prosecution's first witness, said Duncan "went into meticulous detail" about his crimes and discussed how "he had been planning to kill even when he was in prison."

Now retired after 14 years with the FBI, Gneckow and his wife, FBI agent Gail Gneckow, both spoke with Duncan for 7 1/2 hours for the first interview on Sept. 12, 2008.

Gneckow described him as "extremely intelligent."

"He was cordial. He was polite. He was inquisitive, helpful. His demeanor was great," Gneckow said. "It was an extremely productive interview." Gneckow said Duncan described conflicts with his lawyers, including over the subpoena of Shasta Groene's medical records, to which Duncan said he was "totally opposed."

Duncan was just a few credits shy of a bachelor's degree in computer science when he was arrested. He had with him an encrypted computer hard drive that federal authorities still haven't been able to crack.

While Duncan has always taken responsibly for his crimes "he essentially said that the criminal justice system is evil, that the criminal justice system is to blame for what he did," Gneckow said. "He said the death penalty is wrong. It's wrong to kill people. It's wrong to kill and judge people."

"He basically said that the death penalty, where you have a collective group that are making a decision to kill someone, to kill him, is much worse than the crimes he committed....The criminal justice system is doing exactly the same thing that he did, only it's worse," Gneckow said.

Duncan also corrected an assertion from prosecutors at his death penalty trial that he targeted a children's music in Spokane before the Groene murders. Duncan said though the GPS tracker showed he was near Kindermusik, a private music-motion school on the city's South Hill, he was actually interested in a shirtless little boy he'd seen in the area. The boy was adjusting a "for rent" sign outside a nearby duplex.

Duncan said he posed as a renter and had the boy's mother show him around the home. At one point, the woman saw him staring at the little boy.

"She caught me staring at her little boy. I knew from experience, just completely act natural. It was like nothing was wrong," Duncan said, according to the audio recording.

The boy was never harmed.

In another audio recording played in court, Duncan told Gneckow that he "was determined to hurt you, to hurt society. That was my focus. I hated what I was doing, but to me, hurting you was worth it...I would abandon my cats, my career, my job, my family, just so I could hurt you guys."

"That was my sick mentality. I don't believe that anymore. I see things totally differently," Duncan continued. "I'm accused of being inhuman, but what I did was very human. The fact that society turned around and sentenced me to death is a tit for tat. They're doing the exact same thing I did."

He recalled his statement to jurors at the trial, in which he told them that they didn't yet understand the true heinous of what he did. "The true heinousness of what I did was not killing people, not raping children," Duncan told Gneckow. "The true heinousness was the disassociation of myself and the rest of the world, cutting myself off from you people. Making you my enemy."

"The reason I told the jury that was because they were committing the same crime," Duncan told Gneckow. "They don't understand. That is the sickness...Hopefully someone will realize that what I did was perfectly human, and we need to embrace that and accept that if we want to stop this insanity."

On cross examination, Burt questioned Gneckow about Duncan's paranoid behavior, which included covering the camera lens on his laptop computer with a piece of paper because he feared the government could use it to spy on him.

He also questioned Gneckow about statements Duncan made about living in fear while in prison when he was younger and how he talked about having a sickness.

"He referred to it as a sickness, sure, but he didn't refer to it as a clinical sickness," Gneckow said.

Under questioning from Burt, Gneckow said Duncan said he'd been raped in prison. Burt said Duncan confessed after sexually assaulting a boy when he was 16.

Duncan said at the time, "There's something wrong with me. Please help me," Burt said. Burt said Duncan also spoke about being sexually abused as a boy while at a youth ranch.

Gneckow described how Duncan said that, prior to the Groene murders, he considered driving to his father's home and confessing to the murders of the young girls in Seattle. But then he came across a gun and took it as a message from God.

Burt emphasized those statements while cross examining Gneckow.

"He's telling you that a gun became a message from God: 'don't turn yourself in. Go on a crime spree,'" Burt said. Gneckow agreed.