Denver man pleads insanity in murder of woman in argument over dog waste

DENVER (KDVR) -- The Denver District Attorney’s Office said Michael Close, the man accused of killing 21-year-old Isabella Thallas on June 10, 2020, pleaded not guilty by reason of insanity on Monday.

Close is accused of firing at least 24 shots from a high-powered semi-automatic rifle, killing Thallas and injuring her 27-year old boyfriend Darian Simon, who was shot twice in his legs but survived.

The couple was walking their dog around 11:40 a.m. when Close opened his apartment window and allegedly yelled, “Are you going to train that f---ing dog or just yell at it?”

A Denver Police homicide detective testified in a preliminary hearing in November that the shooting followed an exchange of angry words between Close and Simon after Simon's dog defecated in a rock garden outside Close's apartment complex at 3001 Fox St. in the Ballpark neighborhood of Denver.

KDVR-TV FOX31 confirmed the gun used in the murder had belonged to a Denver officer.

Close is charged with two counts of first-degree murder; two counts of criminal attempt to commit murder; two counts of first-degree assault; six counts of using a prohibited large-capacity magazine during the commission of a crime; three counts of possessing a prohibited large-capacity magazine; one count of disorderly conduct; and four counts of the sentence-enhancing charge of crime of violence.

Prosecutors played neighborhood surveillance video in court in a preliminary hearing that showed Close opening his blinds and pointing a high-powered rifle at the couple as Simon bent down to pick up his dog's poop. Moments later Close can be seen firing 24 rounds at the couple, killing Thallas almost instantly, KDVR reports.