Man charged with killing woman walking dog in Colorado pleads not guilty

The man charged in connection with killing a 21-year-old woman and seriously wounding her boyfriend in June in Denver's Ballpark neighborhood pleaded not guilty by reason of insanity.

Michael Close, 37, entered his plea in court Monday morning. His arraignment had been continued from January.

According to Denver Gazette news partner 9News, Close's arrest affidavit states he fired at Isabella Thallas and her 26-year-old boyfriend, Darian Simon, after Simon told their dog to relieve itself near his apartment building in the 2900 block of North Huron Street.

Thallas died in the shooting. Simon was seriously wounded.

Close was arrested in Park County. The Denver Police Department said an AR-15 and a handgun were found in the passenger-side floorboard of the Mercedes SUV he was driving at the time.

A gun belt and firearm magazines were also found, 9News reported.

Close faces 22 charges, including first-degree murder and using a banned high-capacity magazine.

He also faces four sentence enhancers for violent crime. Colorado Bureau of Investigation records show he does not have a previous criminal history in the state.

Close will have a mental health evaluation at the Colorado Mental Health Institute of Pueblo.

Close's charges include two counts each of first-degree murder, attempted first-degree murder, first-degree assault, prohibited use of a firearm, nine counts of using a banned high-capacity magazine while committing a crime and one count of disorderly conduct.

A status hearing is scheduled for May 10 at 8:30 a.m.