Copper Canyon Apartment Homes shooting

The Copper Canyon Apartment Homes shooting was a mass shooting on December 31, 2017, in Highlands Ranch, Colorado. One police deputy, Zackari Parrish, was fatally shot, and four others were wounded. Two civilians were also shot by the gunman, who was later killed in an exchange of gunfire with a SWAT tactical team. The perpetrator reportedly used a rifle and a shotgun. Law enforcement had responded first to a noise complaint, then to a domestic-disturbance call to the apartment. During the second visit, the perpetrator barricaded himself in his bedroom and shot the deputies in an "ambush" style when they entered. The perpetrator was later shot dead by a police tactical team that subsequently re-entered the apartment. It was later determined that the perpetrator, former attorney Matthew Riehl, was a veteran with a history of psychotic episodes and he had recently stopped taking his medication.