In the late evening of August 15, 2017, 35-year-old Thomas Allen Dickinson was fatally shot in a desert area near South Kolb Road and East Science Park Drive in Tucson, Arizona. A security guard who was on duty but not employed by nearby businesses placed a 911 call shortly before 7 p.m. to report the shooting and told Tucson police the encounter began after Dickinson allegedly threw a rock at the guard’s marked security vehicle while the guard was stopped at a red light.

The guard said he followed Dickinson, lost sight of him, then found him in a nearby desert area where an altercation occurred. According to the guard’s account, Dickinson picked up a large rock and the guard fired his handgun once, striking Dickinson. Officers located Dickinson with gunshot trauma; Tucson Fire Department paramedics pronounced him dead. Homicide detectives opened an investigation, and no arrests had been reported at the time of these initial accounts. Dickinson was a Navy veteran and is survived by his parents, a sister, and a brother.

Did anyone in the Tucson area see or hear about a confrontation around South Kolb and Science Park Drive that evening?