PRESCOTT – He stands accused of using a hatchet to bludgeon his sister-in-law and her boyfriend to death and setting the house on fire to destroy any evidence. In a bid to escape the death penalty, he is trying a novel defense:

Scientology made him do it.

Kenneth Wayne Thompson is not arguing that Scientology turned him violent in March 2012. But he is saying his belief in the religion of Scientology helps explain his actions. In particular, he says, his devotion to Scientology's tenets led him on a 24-hour plus drive from his home in rural Missouri to the eventual murder scene in Arizona.

Prosecutors say the marathon drive helps show Thompson committed the crimes with premeditation, an element of the first-degree murder convictions they are seeking. On each, the state of Arizona will ask for the death penalty.

Thompson's attorneys will argue to the jury that the act was rational, if understood through the lens of Scientology. Thompson felt he needed to rescue a child, a nephew to his wife, because the boy's spiritual well-being was at risk.

Neither the boy nor his sister were in the house at the time of the killings.

Raising the defense will make the Scientology belief system part of the court case.

Attorneys for Thompson have already subpoenaed records from the Florida-based church. They have also asked for testimony from Scientology experts, including the actress Leah Remini, who has produced documentaries critical of the religion.

The defense has listed the Scientology "tone scale," a chart that purports to diagram all human emotions,among its evidence.

Potential jurors were asked their thoughts about the religion. Tom Cruise's name was mentioned during opening arguments.

More:Leah Remini claims Tom Cruise knows about abuse in Scientology: 'He's been part of it'

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Prosecutors had tried to get the judge to disallow the Scientology defense. In a brief filed before the trial began, the state said followers of any religion believe the theology to varying degree and it would not be clear to what extent Thompson hewed to Scientology's.

Prosecutors also warned that the trial risked veering down a Scientology rabbit hole.

"Presentation of evidence would have to be proceeded by a complex explanation of exactly what...followers of Scientology believe," prosecutors wrote in a March 2018 argument to the court.

Yavapai Superior Court Judge Patricia Trebesch, who is presiding over the proceedings, ruled in January that the Scientology defense would be allowed.

The role of a religion

Scientology was developed in the 1950s by L. Ron Hubbard, then a science fiction writer. The first meetings of Scientologists were held at Hubbard’s home at the base of Camelback Mountain in Phoenix.

The religion is based on humans being able to achieve spiritual growth by walking a set path and reaching particular milestones. Critics of the religion say those milestones come with a hefty price tag that involve buying books and paying for sessions of introspection called auditing.

In opening arguments last week in Prescott, Kenneth Thompson's defense attorney, Robert Gundacker, asked the jury to see the events that led to the killings through the eyes of Thompson, a devoted Scientologist.

Thompson became a Scientologist as a child, the attorney said, following his mother's marriage to a devotee.

Gundacker told the jury that Thompson had heard that his wife's nephew was undergoing mental health-related treatment, which was anathema to his beliefs as a Scientologist.

"One of the central tenants, and it was core to the whole wider system of beliefs, is that psychology is evil, probably the most evil thing on planet earth," Gundacker told jurors. "Think back to Tom Cruise."

Cruise, the movie actor and Scientologist, famously railed against psychology during an interview on NBC's "Today" show in 2005.

Thompson, as a Scientologist, would have thought that the medication the child was being given subjected him to irreparable harm, his attorney said. In court motions, his defense team has said Thompson thought the child's eternal soul was at risk.

"This is Kenny's mindset," Gundacker said.

Once at the home, his attorney argued, Thompson acted in the heat of passion in killing the victims, not with a murderous intent. Gundacker asked the jury to eventually return a verdict of manslaughter, not first-degree murder.

Prosecutors presented a different theory of the case. Yavapai Deputy County Attorney Steve Young told jurors they would see evidence that showed Thompson's intent, including his marathon drive, his purchases of the hatchet and knife used in the killings and his attempts to cover his tracks by burning the house and telling false stories to police.

Prosecutors did not mention Scientology at all.

Psychology is 'evil and a scam'

Gundacker did not dispute the bare facts of the case. At times, it seemed as if his argument could be used by the prosecution.

Thompson drove from his rural Missouri home to Arizona in a little more than a day. He entered the Prescott Valley home of his sister-in-law and her boyfriend and killed them both, using a hatchet and a knife he had purchased that morning.

He poured acid over the bodies and used flares and diesel fuel to set the house on fire. He got back on the freeway and headed east toward Missouri.

But all of this, Gundacker said, sprang from an innocent motive. Thompson wanted to bring his sister-in-law's two children back home with him.

Thompson's wife had cared for their children while their mother was in prison, Gundacker told the jury. And she and Thompson fretted about their fate once they were back in custody of their mother.

"Kenny Thompson cared so much" about his niece and nephew, Gundacker told jurors, "that he came all the way from Missouri to get them out of that situation. By persuading their mother, not by killing their mother."

Gundacker told jurors that Thompson made the drive on impulse, fueled by worry about the damage being done to one of the children at the hands of mental health professionals at Phoenix Children's Hospital.

"(Scientologists) think psychology is evil and a scam," Gundacker told jurors. "They believe psychology does not only not cure people, it causes mental illness. They think psychological medicines are central to this evil.

"They are part of the scam, and they are particularly bad when they are given to children," he said.

A change of plans, a bloody scene

Thompson did not tell his wife about his plans. She had thought he was on his way to Memphis, Tenn., to deal with issues involving his parents' estate.

Instead, Gundacker told the jury, Thompson arrived at an Interstate 40 junction and decided on a whim to head west not east, toward Arizona to get the children from their mother.

It was a journey of more than 1,400 miles. Thompson drove it in about 25 hours.

He rested at a hotel overnight, court records show, before taking a taxi to the home of his sister-in-law, Penelope Edwards, and her boyfriend, Troy Dunn, the morning of March 16, 2012.

What happened next is not clear. But within an hour, according to a timeline laid out in the opening arguments of both prosecutors and the defense, both Dunn and Edwards were dead.

Edwards’s body was found with 22 wounds to the head and neck, police said, some showing evidence of chopping. Her jugular vein was severed, according to court documents.

Dunn also suffered multiple head wounds caused by something sharp, police said.

A freeway stop and a search

Around 4 p.m., Thompson was driving eastbound on I-40 on his way out of Arizona. A Department of Public Safety trooper monitoring traffic from the median thought there was something unusual about the driver.

He would write in his report that Thompson was “staring straight ahead with both arms locked out and gripping the steering wheel.”

He decided to follow behind him on the freeway, the trooper, Matt Bratz, told jurors in his testimony on Wednesday.

Thompson was driving the exact speed limit, but the trooper eventually found a reason to pull him over, Bratz testified.

The trooper said he detected the smell of a solvent in the car and spotted a red gas can. He also told jurors that he thought Thompson was acting nervously, his chest heaving and his hands shaking as he handed over his license.

The trooper asked Thompson if he could walk his drug-sniffing dog around the car. There is dispute, records say, about whether Thompson gave consent. The dog seemed to hit on something in the trunk and, Bratz said, he told Thompson that gave him license to search the vehicle.

While waiting for a backup officer, Thompson asked if he could retrieve a water bottle from a backpack in the car, the trooper testified.

He also volunteered a tale that, according to the trooper, seemed a non-sequitur: He had stopped by a wildlife park around feeding time and as a worker flung meat into the cages, he ended up getting blood splattered on his clothes and had to change pants.

In the search of his car, troopers found a pair of pants with blood on them, Bratz testified. They also found a hatchet covered in both blood and what appeared to be long human hair.

Bratz told jurors the backpack did not contain the water bottle that Thompson said he wanted to retrieve but did contain a handgun.

Bratz said he radioed dispatch to see if there had been unusual activity in the area and was told that police officers and firemen had responded to a house fire in Prescott Valley. Two bodies were found inside hacked to death and neighbors reported a white car leaving the scene.

Thompson was driving a white Ford Taurus.

'Freaked out' at the crime scene

Handcuffed and waiting by the side of the road, Thompson, according to the trooper’s report, asked if Arizona prisoners were granted conjugal visits.

Jurors in court were shown photos of the hatchet as well as the bodies of the victims, burned both with fire and acid. Two women, escorted by an official from the victim's services unit, left the courtroom while some of the more graphic photos were shown.

Thompson, dressed in a dark suit, aqua shirt and blue tie, appeared to show no emotion throughout the opening day of his trial. Occasionally, he would write notes to his attorneys on a yellow legal pad in front of him.

Following his arrest, Thompson spoke with detectives for more than two hours.

He told the detectives, one of whom testified last week, that when he arrived at the house, he was met with two people strung out on heroin and he acted in self-defense. He initially told police that it was Dunn who was attacking his girlfriend with a hatchet and he intervened.

Thompson told police that he poured acid over the bodies to destroy any DNA evidence. But, fearing that wasn’t adequate, he set the home on fire, records say.

Thompson's attorney, in his opening argument, said Thompson's actions after the murder showed panic, not a calculated plan.

Gundacker said Thompson was "completely freaked out." He imagined for jurors the thoughts that went through Thompson's head. "I was here and the people are dead."

Neither child that Thompson purportedly aimed to rescue was at the home, something prosecutors contend in court filings that Thompson knew. One child was spending spring break with a friend in Bisbee; the other was at Phoenix Children’s Hospital being treated for behavioral issues.

Thought process fits with beliefs

It was that hospitalization that made Thompson worried for the child’s “eternal soul,” according to a filing from Gregory Parzych, one of his attorneys.

Parzych, in a court filing, wrote that he will not argue that Thompson has diminished mental capacity. He will argue that being raised with the beliefs of Scientology, coupled with his diagnosis of Asperger’s Syndrome, made his thinking “linear and concrete.”

Given that mindset, Thompson’s cross-country drive was understandable, his attorneys plan to argue. It also helps explain why he didn't try to have the discussion about the children by phone with his sister-in-law.

Scientology teaches that “what people will not discuss over the phone, or even during a scheduled face-to-face meeting, they will agree to discuss if you show up cold at their door,” Parzych wrote in a December court filing. “Hence, this choice made perfect sense to Mr. Thompson.”

The court docket lists one expert who has agreed to testify about Scientology: Susan Raine, a professor at McEwan University in Alberta, Canada. Raine has researched and written about how science-fiction motifs influenced Scientology.

Raine, in an e-mail, declined to comment on the case.

Parzych filed a potential witness list in September 2017 that included the actress Remini and several other Scientology experts. One of them was Tony Ortega, the former Phoenix reporter for the New Times newspaper and former editor of New York’s Village Voice. His website, The Underground Bunker, is devoted to exposing Scientology and first carried a story about the Thompson case in January.

Parzych seemed to have a difficult time finding a Scientology expert who would agree to testify in the case.

An April e-mail from Parzych, included in the docket by prosecutors, notes that he had reached out to a few experts with little success.

“(W)e have had contacts with a number of individuals who refuse to help once they find out this is a capital case,” he wrote. “Again, we are frantically reaching out to individuals.”

Was he really practicing?

Prosecutors, in pretrial briefings arguing that the Scientology defense not be allowed, noted there appeared to be no evidence that Thompson practiced Scientology at all.

Thompson's grandmother, Eva Harvey, said during a phone interview from her Doniphan, Mo., home, that though Thompson was raised in Scientology from the time he was about 5, he shed the religion as an adult.

"I don't think he really believed it," she said.

Thompson, who until his arrest lived in a house on the same property as his grandmother, was an occasional churchgoer, Harvey said.

But those services were Baptist, she said.

Harvey said she has not been called to testify.

Follow Richard Ruelas on Twitter:@ruelaswritings