Gregory Irving Mack, Ph.D. is a New York State licensed clinical psychologist and a retired "20 year veteran" NYPD Detective Specialist and Police Psychologist. He maintains an independent practice in Westchester County and is employed by the U.S. Department of Veterans Affairs. He is an Assistant Professor of Psychiatry & Behavioral Sciences at New York Medical College; an Adjunct Professor of Psychology at John Jay College of Criminal Justice (City Universityof New York); on the psychological staff of the Institute for Forensic Psychology; an Ad Hoc reviewer for Psychology, Public Policy, & Law, and on the editorial board of Behavioral Sciences of Terrorism and Political Aggression, the official journal of the Society for Terrorism Research.

I have a Ph.D. in clinical psychology, Masters Degrees in both clinical and forensic psychology, and I am a member of American Psychology-Law Society (Division 41) of the American Psychological Association; the American Academy of Forensic Sciences; the Police Psychological Services Section of the International Association of Chiefs of Police, and the Society for Police and Criminal Psychology.

My research interests include police trauma, PTSD, forensic decision-making, dangerousness, suicide by cop.