On August 15, 2017, at approximately 6:45 p.m., Tucson Police officers responded to the intersection of South Kolb Road and East Science Park Drive for a report of a shooting. Upon arrival, officers spoke with a security guard who advised he was involved in the shooting and the one who called 911.
The guard directed officers to a desert area northeast of the intersection. In the desert, officers located 35-year-old Thomas Allen Dickinson on the ground with obvious signs of gunshot trauma. Dickinson was pronounced deceased on scene.
Homicide detectives were able to determine that the security guard was on duty, but not affiliated or working for the businesses in that area. The guard was traveling in his marked security vehicle from one job site to another. While stopped at the red light at E. Science Park Drive, he reported that an unknown male threw a rock at his vehicle. The guard turned east on to Science Park Drive in an attempt to confront the subject about the incident. The guard lost sight of the male and then relocated him in the desert area northeast of the intersection and an altercation ensued. During the altercation, the male subject reportedly picked up a large rock and the guard fired a handgun at the subject, striking him one time.
Detectives are still trying to determine specific details about the incident.