Park Dietz

Park Elliot Dietz, born in 1948, is a distinguished forensic psychiatrist renowned for his involvement in some of the most significant criminal cases in the United States. His expertise has been sought in high-profile trials including those of Joel Rifkin, Jeffrey Dahmer, Arthur Shawcross, the Unabomber, Richard Kuklinski, and the Beltway sniper attacks, as well as Jared Lee Loughner. Dietz gained national recognition in 1982 when he served as the prosecution’s expert witness during the trial of John Hinckley, Jr., who attempted to assassinate President Ronald Reagan on March 30, 1981. At that time, Dietz was an assistant professor at Harvard Medical School, where he argued that Hinckley was aware of his actions and understood their wrongfulness, thus negating an insanity defense.

In addition to his psychiatric work, Dietz is a pioneering criminologist who established the field of workplace violence prevention in 1987 by founding Threat Assessment Group, Inc. (TAG). This organization focuses on evaluating and managing threats, stalking, and risks stemming from domestic violence in corporate, educational, and public environments. By 2013, over 20,000 corporate leaders had benefited from TAG's training programs.

Dietz also leads Park Dietz & Associates (PD&A), a forensic consulting firm that offers insights into criminal behavior and forensic sciences, catering to both criminal and civil litigators. With a team of experts, including physicians and retired FBI agents, PD&A is recognized for its comprehensive approach to forensic issues. Both TAG and PD&A operate out of Southern California, with PD&A maintaining an additional office in Washington, D.C.