MALHEUR COUNTY, Oregon -- After 20 years faking insanity, and despite warnings from doctors, a Nampa man released from an Oregon psychiatric hospital is now charged with murder.

49-year-old Anthony Montwheeler was released from the Oregon State Hospital in December. Just weeks later, he allegedly stabbed his ex-wife to death and hit and killed a Vale man while escaping police on the highway.

KTVB filed public records requests with the Oregon Psychiatric Security Review Board after learning about Montwheeler's past from the Malheur Enterprise - a mom and pop newspaper in eastern Oregon. They were forced to fight the state agency to get ahold of remaining records.

MORE: E. Oregon newspaper battles state agency for public records

KTVB's Morgan Boydston went through hundreds of pages of records for days - including medical notes, risk assessments and court documents - as well as an hours-long audio recording. What she found is very troubling and, at times, chilling

Mr. Montwheeler put on a decades-long facade, one that records show doctors suspected since the beginning. He admitted to feigning insanity for 20 years at a hearing in front of the Psychiatric Security Review Board on Dec. 7, 2016.

"I had a choice: either I could go to prison or I could go to the hospital," Anthony Montwheeler told the Psychiatric Security Review Board in December, "which I can go to hospital for six months and all I got to do is make myself sound like I'm crazy. And that's the route I took.

Abusing the mental health system for two decades, saying he received special treatment and didn't have to pay rent. One board member replied, "It's room and board... on the state's rent" to which Montwheeler agreed.

Shocking new details outline how different psychiatrists and psychologists suspected Montwheeler was faking his mental illnesses since his admission to the Oregon State Hospital in 1997. But state officials did nothing about Montwheeler's ploy until he admitted it in 2015.

MORE: Malheur County murder suspect feigned insanity for 20 years to avoid prison

So how did he get into the system in the first place?

In 1996, Montwheeler allegedly choked his wife and threatened to take their child and run away to California. His wife, Rosa Montwheeler, attempted to have her family pick her up and remove her from the situation. But Montwheeler found out about the arrangement, and forcibly took Rosa and their child hostage, threatening their lives at gun point. Police say he pointed a rifle at family members and fired three shots into the ceiling. A several-hour standoff with police ensued. Montwheeler eventually surrendered to police and was taken into custody.

He was convicted of two counts of kidnapping with a firearm with the intent to terrorize and six counts of unlawful use of a weapon.

A psychiatrist then diagnosed Monthwheeler, a former Marine and ex-correctional officer, with psychosis and manic/depressive behavior.

"That has formed the basis of the diagnosis ever since," Oregon State Hospital psychiatrist, Dr. Mukesh Mittal, MD, said.

Montwheeler plead guilty except for insanity and has been under the jurisdiction of the Security Review Board ever since.

After reporting symptoms, doctors diagnosed him with bipolar disorder and Post Traumatic Stress Disorder (PTSD). But over the years, several other psychiatrists and psychologists documented his symptoms were in full and sustained remission.

Dr. Mittal, who evaluated Montwheeler last year, said in the December hearing that he had never seen evidence of bipolar disorder firsthand in Montwheeler.

"That is my argument: I think he never did have bipolar disorder, that there's only one record that suggests he had symptoms, which he reported and have not been observed," Dr. Mittal said.

Some medical staff at the Oregon State Hospital struggled to treat Montwheeler, saying his diagnosis and symptoms were unclear. Assessments over the years include different evaluations on his risk for violence if released; some evaluations determined he was fit for conditional release with proper supervision and treatment in the community, other saying he was not.

Records show he caused trouble while at the hospital: he was caught loan sharking and taking advantage of other patients financially. He was released from OHS in 2002 but still under the Security Review Board's jurisdiction. After committing more crimes, he was sent to prison in 2012 and returned to OHS in 2014.

In 2016, hospital staff said they believe he was "improperly placed" in the board's jurisdiction and was never mentally ill.

"I'm assuming somebody in the system might do a forensic look at this and figure out what the hell happened," Psychiatric Security Review Board Acting Chair, Kate Lieber, said in the December hearing.

Rather than bipolar or PTSD, medical professionals believe Montwheeler has anti-social personality and adjustment disorders. Deemed no longer mentally ill by the board at the hearing in December, his request to be released from their jurisdiction was granted.

"Truthfully, I was scared," Montwheeler told the board. "I didn't want to do seven years in prison with me being an ex-correctional officer. I didn't want to get shanked."

In that same hearing, a psychologist who evaluated Montwheeler for about two years before his release warned that he was still dangerous.

"I concluded that in an institutional setting he would be at low risk for violent acts and if he were in the community with supervision, it would be a moderate risk," Dr. Brian Hartman, PsyD, said in the hearing. "If in the community without supervision, his risk of violence would be high. And it would be most likely to target intimate partner or other family members."

Which is exactly what he is accused of doing.

"Your tendencies to think that that's the way you should go through life is just troubling and I can only see that if you continue with those kind of thinking errors, of which they are, enormous thinking errors, that you're just going to be right back in prison, exactly where you didn't want to be, so this is no win for anybody here," Lieber told Montwheeler.

Weeks after his release, a series of tragic events unfolded: police say Montwheeler kidnapped his fourth ex-wife Annita Harmon and stabbed her to death near Weiser. While escaping police, officers say he got into a head-on collision near Ontario and killed the driver of the other car, David Bates of Vale, Oregon.

"My sincerest hope is that you go out and make the best of this second chance that you've been given. because that's exactly what it is, it's a second chance," Lieber told Montwheeler in the hearing. "And you can either screw it up or you can do the right thing, and my hope is you'll do the right thing. I'm sincerely worried that you won't."

Medical professionals said in the December hearing if Montwheeler commits a crime or becomes dangerous in the future it is due to his personality disorder.

A hospital staff report from 2016 said Montwheeler would need close supervision if released. That same report says if Montwheeler is discharged from the board's jurisdiction, they no longer have domain over him.

Montwheeler is scheduled to enter a plea to charges of aggravated murder, assault and kidnapping in Malheur County next week. If convicted, Montwheeler could face up to life in prison or the death penalty.

MORE: Nampa man indicted on murder charges after Ontario kidnapping, crash

KTVB expects to receive more documents by the end of the week and will continue to update this story.