Denver man found guilty in Dog Walker Murder Trial

Posted at 3:24 PM, September 23, 2022 and last updated 12:41 AM, December 13, 2022

By Stephanie Butzer

DENVER (KMGH) — A man accused of murdering a woman and injuring her boyfriend while they walked their dog in the Ballpark neighborhood in June 2020 has been found guilty of first-degree murder.

The jury reached a verdict shortly before 2:30 p.m., convicting 38-year-old Michael Close in the murder of 21-year-old Isabella Thallas for one count of first-degree murder – after deliberation and one count of first-degree murder – extreme indifference, two counts of attempt to commit first-degree murder, and two counts of first-degree assault.


The charges against Close stemmed from a shooting in June 2020 in Denver’s Ballpark neighborhood. On June 10 of that year, Close was accused of using a firearm he took from a Denver police officer — a longtime friend of his — to shoot Thallas and her boyfriend, 27-year-old Darian Simon, while they walked their dog outside an apartment complex.

Close’s attorneys claimed he suffered a mental break and “did not know what he was doing” when he opened fire on the couple, according to The Denver Post. His public defenders told jurors he committed the shooting, but argued during opening statements that Close should nevertheless be found not guilty because he was legally insane at the time of the attack.

Michael Close (Denver District Attorney’s Office)

Denver District Attorney’s Office prosecutors dismissed that argument, telling jurors Close was sane during the shooting and acted on long-boiling rage because he felt disrespected in other areas of his life, The Denver Post reported.

Following the verdict, Denver7 spoke with Thallas’s mother, Ana Hernandez Thallas. She said it has been a week from hell as she sat through the trial, heard every witness and saw all the evidence — reliving her daughter’s murder.

“Even though justice with Michael Close was served, my daughter is still dead,” she said. “Bella is gone. Nothing is going to bring her back. As a mother — it’s almost like a swimming pool you’ve drowned in. You never quite breathe the air. And I’m ready to breathe the air.”

Despite getting the verdict she wanted, it didn’t seem like enough.

“I’ve waited this long for this?” she said. “Why don’t I feel different? Why can’t I be happy? It’s because Bella is dead. That’s the reality of it.”

Close didn’t seem to show remorse, she said. She said the only time he cried was when his girlfriend testified against him.

Through the pain, the mother has found some peace advocating for gun and domestic violence victims.

The trial for Close began on Monday. After closing arguments in the mid-morning Wednesday, the jury was left to deliberate. Those deliberations continued into early Thursday afternoon before the verdict was reached around 2 p.m. The jury deliberated for less than a day.

Isabella Thallas (Courtesy Thallas family)

A probable cause statement for his arrest states Close yelled at Thallas and her boyfriend about their dog defecating on the ground near the apartments before firing upon them.

Close allegedly fled from the scene. Jefferson County authorities later contacted him off of U.S. 285 and Close was arrested.

Court records show he was charged with: one count of first-degree murder after deliberation; one count of first-degree murder – extreme indifference; one count of attempted first-degree murder after deliberation; one count of attempted first-degree murder – extreme indifference; one count of first-degree assault with a deadly weapon; one count of first degree assault – extreme indifference; six felony counts of possession of a large-capacity magazine during a crime; three misdemeanor counts of possession of a prohibited large-capacity magazine; two misdemeanor counts of prohibited use of a weapon; one count of disorderly conduct for possessing a firearm; and four possible sentence enhancers related to the commission of a violent crime and use of a weapon.

On March 8, 2021, Close pleaded not guilty by reason of insanity. Following a health evaluation, he was found fit to stand trial and the motion was dismissed.

Court testimony from June 2021 showed that Close texted and left a voicemail on the day of the shooting for the Denver police officer from whom he is accused of stealing a rifle used in the shooting. In January 2021, the Denver Police Department confirmed the AK-47 used in the shooting was the personal weapon of Denver police officer Dan Politica. In a voicemail, Close told Politica something along the lines of “something along the lines of ‘dude, Dan, I really f—ed up bad. I did something really bad. There’s no, there’s no going back from this now,'” according to lead detective Joseph Trujillo.

Politica filed a resignation letter Feb. 13 and left DPD one month later for reasons unrelated to this case.

In September 2021, the Isabella Joy Thallas Act, which requires gun owners to report lost or stolen firearms to law enforcement within five days of realizing it was missing, went into effect in Colorado. Gov. Jared Polis had signed the bill the previous April. Earlier that month, the Colorado House on Monday passed the Lost or Stolen Firearms bill (SB21-078), which was renamed via an amendment to honor Thallas.

On the day it was signed into law, Thallas’ mother, Ana Thallas, was in attendance.

“After I reviewed the bill, it made sense to me. Common sense,” she said. “Unfortunately, as we all know, common sense is not always so common. So, I fight — not just for Isabella, but I fight for the other people in Colorado because it’s not just about her. It’s about (her son) Jacob, when he goes to school and his school might be next. The grocery stores, the malls — the gun violence is out of control. Somebody has to do something. But what saddens me and hurts the most is that it takes a mother of a murdered daughter to stand up and speak and try and make a change and a difference in this state.”

Close’s sentencing is set for Nov. 4, 2022.

This story was originally published Sept. 22, 2022 by KMGH in Denver, an E.W. Scripps Company.