Crisis negotiation is a law enforcement technique used to communicate with people who are threatening violence (workplace violence, domestic violence, suicide, or terrorism), including barricaded subjects, stalkers, criminals attempting to escape or evade arrest, and hostage-takers. Crisis negotiation is often initiated by the first officer(s) on the scene. History Modern hostage negotiation principles were established in 1972 when New York City Police Department detective Harvey Schlossberg, also a psychologist, recognized the need for trained personnel in crisis intervention. Schlossberg had worked on the David Berkowitz ("Son of Sam") case, and had instituted other psychological principles in police work, including psychological screening of police applicants and the use of hypnosis in suspect/witness interviews. Schlossberg's negotiation strategies were used during the 1973 New York City hostage incident and were crucial in ensuring the peaceful resolution of the standoff.The first hostage negotiators were often deployed as elements of police tactical units and merely created a diversion while they deployed. In modern...