Police say that Harmon apparently took his own life due to a self afflicted gunshot wound.
Harmon, 70, was suspected of opening fire in an office building in central Phoenix on Wednesday. This latest shooting incident took place following a legal mediation meeting. Harmon fled the scene in a 2013 Kia Optima.
Reuters reported that television news images displayed the suspect's white Kia Optima parked in the lot of a Bass Pro store in Mesa, southeast of Phoenix.
The vehicle was surrounded by crime scene tape, with police vehicles parked in the resounding area.