A household dispute in Florence, Colorado, ended in the death of 64-year-old John Achterkirch on the evening of July 28, 2020. Tensions had been rising in the home he shared with his niece, Danyelle Shatto, and her fiancé, 56-year-old Mark Nielsen, after another resident, Joleigha Johnson, moved in and was later arrested on an outstanding warrant. Achterkirch reportedly blamed Nielsen and Shatto for that arrest and threatened to evict them.

On the night of the shooting Nielsen later told police Achterkirch had assaulted him and threatened to kill him and Shatto. Nielsen was armed with two handguns and fired a shot that struck Achterkirch in the face. Achterkirch was found on the floor, taken to a hospital, and died a few hours later. Nielsen suffered forehead lacerations, received medical treatment, and was arrested on suspicion of second-degree murder after the incident. His statements to police changed during the investigation; he later said intoxication and marijuana contributed to inconsistent accounts.

Readers who knew John, the household, or observed events in Florence around that date are asked to share any information that might help clarify what happened.