Smith said the Utah Department of Public Safety would investigate Stewart's death.
On Wednesday, Stewart, 39, had experienced a courtroom defeat when a judge rejected defense attorneys' arguments that a police officer lied to obtain the "knock-and-announce" warrant that led to the raid on his home during which an Ogden police officer was killed and five others were wounded.
"I just think [Wednesday's] hearing hit him really hard," Erna Stewart said Friday. "I just think he couldn't bear it anymore."
Attorneys for Stewart had asked 2nd District Court Judge Noel Hyde for a hearing to determine whether Weber Morgan Strike Force Agent Jason Vanderwarf included false or misleading statements in a search warrant affidavit related to marijuana cultivation.
Erna Stewart said no one had the chance to talk in depth with Matthew Stewart after Wednesday's hearing, adding that attorney Randy Richards was planning to visit him in the jail Friday, and she was planning on visiting him Friday evening with her husband, as they do every week.
"We were supposed to see him this evening," she said. "It just came like a shock. It just hit us like a brick. We didn't expect it."
Erna Stewart said her brother-in-law had given no indication to them that he was considering ending his life. If he had, she said the jail likely would have put him into lock down or in a more secure cell.
Stewart is the third suicide at the jail since last November.
On Nov. 14, 43-year-old Jeffery Dean White was discovered hanging from a bed sheet in his cell. White, facing trial for murder in the death of his girlfriend, 38-year-old Marnie Stark, was being housed in a maximum security unit and was not on suicide watch.
On Dec. 9, 22-year-old Ieve Dominguez was found dead, also after himself with a bed sheet.
"He was only facing some misdemeanors, minor stuff. He had been seen by a health worker on Thursday. We do screenings on all inmates and there was no indication of him being depressed or considering suicide," said Sheriff's Chief Deputy Klint Anderson at the time.
"It is unusual for us to have two in a month," Anderson added, estimating that the jail typically may have "two or three" prisoner suicides in an entire year.
During a Friday morning news conference on Stewart's death, Weber County Sheriff Terry Thompson said all jail protocols were followed, including hourly checks on Stewart 24 hours a day. He said Stewart chose not to avail himself of the mental health services that are offered to all inmates.
"Mr. Stewart has been treated in an appropriate and humane way," Thompson said.
Prior to Thompson's remarks, Smith recounted the events of Jan. 4, 2012, saying that Stewart knew he was shooting at police officers when they entered his house and continued to shoot at them after they were wounded.
"These officers' actions were heroic and they followed the law every step of the way," said Smith, who also referenced the ruling upholding the legality of the search warrant.
Erna Stewart said their family was feeling down after Wednesday's hearing, feeling like it was "obvious" that Vanderwarf lied in the warrant, and the judge refused to entertain the motion. If her brother-in-law had felt more upset than they were about the denial of the motion, she said it wouldn't be surprising that he ended his life.
"It shouldn't come as a shock, but it really was," Erna Stewart said.
Stewart had pleaded not guilty to a charge of aggravated murder and seven first-degree felony counts of attempted aggravated murder for allegedly trying to kill other officers, and one second-degree felony count related to alleged marijuana cultivation. According to court documents, 16 pot plants were found in his house after the raid.
One of Stewart's attorneys, Bernard Allen, said he found it hard to believe that his client had committed suicide. Allen said while Stewart was "a little bit depressed" about losing the bid for a hearing on Wednesday, he and other attorneys were not concerned that Stewart might take his own life.
"None of us were losing hope in the case," Allen said. "We didn't really sense anything. His whole family was there [in court Wednesday], and we had a long chat after the hearing with his family about the things we still had. It was a setback, but certainly not the end."
Allen said Stewart's attorneys will want answers about conditions in the jail and how carefully Stewart was being monitored.
"Obviously, we will look into the details of it," he said. "It's a good family. They are good people. They are incredibly supportive of Matthew and my heart certainly goes out to them. This whole thing has been a horrible ordeal for them."
The family announced Stewart's death early Friday morning on his Facebook page. The statement primarily castigated law enforcement and the courts for how they handled Stewart's case.
"Our family regrets to announce that our son Matthew David Stewart is in the hands of his creator after a long and courageous battle with a corrupt and arrogant judicial system," the statement read.
"He was supposed to be considered innocent until he was proven guilty beyond a reasonable doubt," the statement continued. "After the illegal assault on his home by a gang of thugs and his inhumane treatment at the Weber County Correctional Institute, along with the recent loss of an unfair and unjust ruling by the court, Matthew gave up hope of his ever getting justice in his case."
The statement concluded: "Matthew is not in any more physical and emotional pain and free from this world of hurt and unfairness. May those who were responsible for this terrible actions of January 4, 2012 have it on their consciences and it is hoped that they will be continually reminded and someday answer for their crimes against humanity."
The oldest of five children, Stewart had served as an Army multichannel transmission systems operator in North Carolina and Germany for four years. He was awarded the Army Achievement Medal and a National Defense Service Medal before leaving the military in 1998, an Army spokesman said. He worked as a security guard for the IRS before getting a warehouse job on the graveyard shift at Walmart in Riverdale, where he was employed at the time of the raid.
Tipped off by an ex-girlfriend that Stewart was growing marijuana in his house, police obtained a search warrant. After the raid, police reported they had seized 16 plants.
Tribune reporter Michael McFall contributed to this story.
Twitter: @remims Full text of Stewart family statement:
Our family regrets to announce that our son Matthew David Stewart is in the hands of his creator after a long and courageous battle with a corrupt and arrogant judicial system. He was supposed to be considered innocent until he was proven guilty beyond a reasonable doubt.
Unfortunately this system has become so perverted that those people that are in power that are in power are able to lie and justify their actions after purposely violating someone's civil rights and the rights that were supposed to be protected by the Constitution of the United States of America. After the illegal assault on his home by a gang of thugs and his inhumane treatment at the Weber County Correctional Institute,along with the recent loss of an unfair and unjust ruling by the court, Matthew gave up hope of his ever getting justice in his case.
Our hearts go out to all of those who believed in Matthew and appreciate both their financial and unwavering support by all of those who knew him and those who did not have the pleasure to know what a free and loving spirit he had. It is another devastation to all of us that comes with the territory in trying to fight the tyranny of a one sided corrupt system of government where those in power will cover up their mistakes and justify their actions at any cost. Even when they know the truth of their deceit will cover it up and protect those who are responsible in an effort to preserve this system that they have created.
Matthew is not in any more physical and emotional pain and free from this world of hurt and unfairness. May those who were responsible for this terrible actions of January 4 2012 have it on their consciences and it is hoped that they will be continually reminded and someday answer for their crimes against humanity
-The Michael Stewart Family