David Allen Grossman was born on August 23, 1956. He is an American writer and teacher who gives talks about how people think about using deadly force. He was a lieutenant colonel in the United States Army and has retired from the military.

Post-military life

After retiring from the Army, Grossman started the Killology Research Group to give presentations about the physical and mental effects of using deadly force on law enforcement officers and soldiers.

Grossman also speaks at events for the public about ways to reduce violence in society and how to handle what happens after violent events, such as school shootings. As a civilian, Grossman has given expert opinions in many state and federal court cases and was part of the team that prosecuted Timothy McVeigh in the United States vs. Timothy McVeigh case.

In 2022, the Killology Research Group changed its name and brand to Grossman On Truth.

Works

Grossman's first book, On Killing: The Psychological Cost of Learning to Kill in War and Society, examines the mental processes involved in killing another person. He explains that most people experience a strong fear of violence and that soldiers must be trained specifically to overcome this fear and kill. He describes physical effects caused by violent stress, such as seeing only a small area (tunnel vision), changes in how people hear sounds, and conditions like post-traumatic stress disorder. Robert Engen, in an article for the Canadian Military Journal, criticized On Killing, stating that while the book is a good starting point, it has many problems that prevent it from being the final authority on the topic. Grossman responded in the same journal, explaining that S. L. A. Marshall's research—despite being questioned—has been supported by later studies and real-world experience. He added that these findings have shaped military and police training for more than 50 years. On Killing has been cited over 3,300 times, according to Google Scholar.

In Stop Teaching Our Kids to Kill: A Call to Action Against TV, Movie and Video Game Violence, Grossman argues that techniques used by armies to train soldiers to kill are similar to those found in certain video games. He claims that playing violent video games, especially first-person shooter games where players use a controller shaped like a weapon, teaches children how to use weapons and desensitizes them to the act of killing by having them simulate killing many opponents in one game. He often refers to these games as "murder simulators."

His third non-fiction book, On Combat: The Psychology and Physiology of Deadly Conflict in War and in Peace, builds on his first book. It provides strategies for managing the physical and mental effects of violence for people who kill as part of their jobs, such as soldiers and police officers.

Criticism

University of Nebraska criminal justice professor Samuel Walker described Grossman's training as "okay for Green Berets but not acceptable for domestic policing." He noted that the best police chiefs in the country do not want to use this type of training. In 2019, Minneapolis Mayor Jacob Frey banned what he called "fear-based training," which included Grossman's seminars. A statewide ban in Minnesota was passed into law in 2020.

Patents

• Firearms Safety Patent: Ergonomic Grip for a Slide of a Semiautomatic Firearm, Inventors: David Grossman and Jon Grossman, Patent No. D697,997
• Firearms Safety Patent: Off-Trigger Locator for a Firearm, Inventors: Bruce Siddle, David Grossman, and Jon Grossman, Patent No. 8,671,605, Patent No. D697,996
• Firearms Safety Patent: Off-Trigger Locator Attachment, Inventors: Bruce Siddle, David Grossman, and Jon Grossman, Patent No. D701280
• Firearms Safety Patent: Safety Index for a Firearm, Inventors: David Grossman and Jon Grossman, Patent No. D697,998
• Firearms Safety Patent: Micro-Front Sight for a Firearm, Inventors: David Grossman and Jon Grossman, Patent No. D701284