The mother of the gunman who opened fire Sunday in Douglas County – killing a sheriff's deputy and wounding six other people – said in November that he was suffering from post-traumatic stress disorder and was “off his medication,” 9Wants to Know has learned.

And 9NEWS has also learned that in 2014 Matthew Riehl walked away from a mental health facility where he was being treated after suffering a “psychotic episode,” according to communication from the U.S. Veteran's Administration to U.S. Rep. Mike Coffman provided to 9Wants to Know by his office.

Riehl served in the Wyoming Army National Guard and deployed to Iraq in 2009.

The incident at the mental institution occurred in Sheridan, Wyoming, according to the report provided to Coffman.

During that stay “the veteran escaped/eloped from the mental health ward, was located and brought back, and placed on a 72 hour mental health hold,” according to the report.

The shooting occurred in Coffman's district, and his staff has already been in contact with the VA to seek further information about this case, spokesman Daniel Bucheli told 9NEWS.

Taken together, the reports by the University of Wyoming police and the Veteran's Administration further fill in the picture of Riehl, 37, as a man with serious mental health issues.

Riehl apparently called the police to his apartment early Sunday morning after recording a rambling profanity-laced examination of his life, his roommate and his problems with local law enforcement. A video he posted online included footage of his initial interaction with officers.

Later, Douglas County Sheriff Tony Spurlock said Riehl ambushed those officers, killing Douglas County sheriff's deputy Zackari Parrish and wounding three other deputies and a Castle Rock police officer as well as two neighbors.

Riehl, who died after a confrontation with SWAT officers, fired more than 100 rounds, Spurlock said.

According to the report provided to Coffman's office, after the episode in Sheridan, Riehl was cared for by the Veterans Administration hospital in Rawlings, Wyo., then in Cheyenne and later in Eastern Colorado.

He was seen as an “urgent contact” for a mental health issue July 22, 2015, in Colorado. He skipped a mental health appointment Nov. 3, 2015, and another one July 28, 2016. He also skipped several other medical appointments, according to the report.

The comments by Riehl's mother are contained in a University of Wyoming police report that details an investigation into allegations that Matthew Riehl, a military veteran and graduate of the UW law school, made inflammatory comments on social media.

The University of Wyoming police reports, obtained Tuesday by 9Wants to Know, detail the investigation into a series of disturbing posts attributed to Riehl on social media.

The first report was filed Oct. 30 by Klint Alexander, dean of the university's law school, over comments that Riehl had posted online. Although Riehl did not specifically threaten anyone, Alexander told police he was concerned because the veteran had previously talked about gun violence, according to the report.

It appears from the report that the officer told Alexander it wasn't a criminal matter. The officer tried to reach Riehl but was unsuccessful, according to the report.

Then, on Nov. 7, assistant dean Lindsay Hoyt filed a follow-up report, pointing officers to a Facebook page tied to Riehl. One post showed a picture with a caption “shot that m----------- dead on the streets of Laramie” and another included a map of the area around a Texas church where 26 people were killed.

University police officers talked with multiple people as they followed up, according to the report.

Susan Riehl told a university police officer on Nov. 7 that her son “still frequently contacts her via email and makes inflammatory statements about her being a 'tranny prostitute,'” according to the report obtained by 9Wants to Know.

When the officer asked why she thought he did that, she “stated that he was off his medication and was suffering from PTSD from a deployment in 2009.”

She went on to tell the officer that her son “was angry and often attempted to use his law degree to intimidate and get his way with people when they would try to intervene in his life.” She said he frequently threatened to file lawsuits, was “arrogant,” and “wanted to incite people and beat them legally.”

Susan Riehl also expressed the hope that her son could get help at a Veterans Administration hospital.

Riehl's brother, Peter Riehl, told Wyoming officers that the man “is bipolar and had a manic breakdown about four months ago.”

Peter Riehl said that his brother had “since refused all contact with his family,” according to the report.

The report also details the interaction of a university police officer with officers in Lone Tree where Riehl's parents live, Rawlins and Cheyenne.

In Lone Tree, police investigated Riehl for false reporting after claiming that his mother and brother had created a suicide pact.

Ultimately, the university officer requested that Lone Tree police attempt to contact Riehl to check on his mental state. Because Lone Tree officers had recently issued him a ticket, they did not make a separate attempt to contact him.

But, according to the report, Lone Tree officers were aware Riehl had guns. They did issue a statewide bulletin on Riehl “so that other officers in the state would be made aware of the situation.”

It was not clear from the reports exactly what was contained in that bulletin – nor whether the officers who responded to the Copper Canyon Apartments on Sunday morning were aware of it.

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Contact 9NEWS reporter Kevin Vaughan with tips about this or any story: kevin.vaughan@9news.com or 303-871-1862.