But sheriff's officials say monitoring inmates and assessing their mental health issues is a constant challenge.
In response to an open-records request from The Salt Lake Tribune, the Weber County Attorney's Office turned over hundreds of documents gathered by investigators in preparation for a 2014 trial including journals found in Stewart's home that detail his struggle with suicidal thoughts.
Stewart was accused of opening fire on Weber Morgan Strike Force officers serving a search warrant at his Jackson Avenue home around 8 p.m. on Jan. 4, 2012. Agent Jared Francom was killed in the shootout, and five other agents were wounded. Stewart also was injured in the shooting.
Among police reports, scene reconstructions and interview transcriptions with witnesses are scanned images from journals kept by Stewart. Some of the entries date back to 2000, and sister-in-law Erna Stewart said he kept the writings while he was in the military.
The journals are filled with doodles, musings about recent dreams, a treasure map and a list of items needed to begin his basement marijuana grow. The title on one page, which is filled with a checklist of growing supplies, exclaims: "Creating my Eden from the ground up!"
But Stewart also wrote often about suicide, stating that he had wished he was dead since he was a child.
"Suicide is derived from an all-encompassing and constant anger and sorrow at everything, especially at one's self," he wrote. "The suicidal person starts trying to find ways of striking back at all the ugliness that surrounds them in a dark illusion and vile lies. When finally they become frustrated at their own helplessness, weakness and confusion, the last and only way they see out of the absolute madness is to end it all."
Supplemental reports from responding police officers to the Jan. 4 shooting also indicate that Stewart may have had suicide on his mind.
South Ogden police Officer Dan Buttars was assigned to stand watch over Stewart at the hospital after the shooting. In his report, he wrote that the shooting suspect told him from his hospital bed that he hated life and was trying to make his own antidepressant, seemingly in reference to the marijuana grow in his basement.
"Stewart said there have been very few days that he does not think about committing suicide," Buttars wrote. "I asked if he had a plan to commit suicide, and he said yes. Stewart said, 'This was kind of it.' "
EMT worker Benjamin Williams, who treated Stewart as they rode to a hospital in an ambulance, wrote in his report that Stewart seemed quiet and peaceful during the ride, and though he hardly spoke, he made one reference to death.
"Inside the ambulance he complained of the handcuffs being too tight," Williams wrote. "Officer Weise said, 'We're trying to save your life,' and Stewart said, 'You're not doing me any favors.' That's all I heard him say."
And when he was apprehended in a backyard shed after the shootout, one officer wrote in his report that he heard Stewart tell officers, "Just shoot me."
But while authorities apparently had evidence that Stewart had a history of suicidal thoughts, that information may not have been relayed to Weber County Jail officials.
Weber County Sheriff's Lt. Mark Lowther declined to speak specifically about Stewart's suicide, citing an ongoing investigation by the Utah Department of Public Safety. Speaking of general practices, Lowther said it would be uncommon for jail authorities to search through an inmate's case file. So if a supplemental report from an officer indicated that an inmate was suicidal as in Stewart's case jail officials would likely be unaware.
"We're releasing and booking all day long," Lowther said. "It's just not practical to read every report. All we are pretty much concerned with is charges; we really don't care about the specifics of the crime."
Lowther said the jail has two mental health officials on staff to help inmates. He said inmates most often are placed on suicide watch based on their self-admissions, reports from the officer that booked the inmate into the jail or if a family member indicates an inmate might be suicidal. Lowther said mental health issues are challenging for jail workers because the jail population is constantly fluctuating, and it's not always easy to tell who is suicidal.
"We've had people be very, very discreet, and very covert in their effort to do it," he said. "And then we've had individuals stand in front of an officer with a sheet tied around their neck. ... The jail is a unique place. In society in general, not a day goes by that our deputies don't respond to one threatened or completed suicide. They still have those emotional problems [when they are in the jail] and, oftentimes, that's compounded because now they are incarcerated."
Erna Stewart said her brother-in-law suffered from social anxiety and depression, but was never diagnosed as such because he refused to seek treatment from a medical doctor, opting instead to treat himself with essential oils and other "natural" remedies.
"He did not believe in going to the doctor, and getting on Prozac," she said. "Matthew was not into that at all. That's why he was doing what he was doing [growing marijuana]."
The sister-in-law said that in the months before the fatal shootout, Matthew Stewart had seemed happier than he'd been in a long time. But as she and her husband visited the jail weekly in the last year and a half, she could see the inmate's spirits begin to sink.
"He never said he was thinking of suicide," she said. "But you could read it on his face that he was struggling."
After Stewart's death, Weber County Sheriff Terry Thompson said during a news conference that the man had never taken advantage of the mental health workers available to him at the jail. But Erna Stewart said her brother-in-law was concerned about talking about his feelings with someone employed by the jail.
"He didn't feel safe speaking with anyone in there," she said. "That's what he told us. Basically, he couldn't talk openly, because he thought they could use it against him [at trial.]"
Matthew Stewart was kept in a maximum-security cell alone, Erna Stewart said, and was allowed out for one hour every other day. He was never put on suicide watch, she said. He was allowed five photos in his cell, Erna Stewart said, and all of his written communication came in the form of small, one-sided postcards.
Erna Stewart said Matthew Stewart and his parents filed numerous complaints with the jail about how he was treated, the food that he was given and the frustration over technology issues with the video-monitoring system for jail visits, but no change ever came. She believes jail officials could have done more to prevent his death.
"First of all, treat people like they aren't already convicted," she said. "Matthew was already [hanged] that night [of the shooting.] They [jail workers] hated him. He was labeled a cop killer. Who was going to protect him?"
Lowther said all inmates charged with homicide are put on a watch for a period of time to access their mental state. He said county officials are currently doing a study about suicide both inside and outside of the jail, since the acts affect their deputies working out on the street. "There are literally some days we respond to more suicide calls than we do automobile accidents or thefts," Lowther said.
Stewart is the fourth person to commit suicide in the Weber County Jail since November.