Crisis negotiation

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 after a botched robbery, and hostage-takers. Crisis negotiation is often initiated by the first officer(s) on the scene.

Modern hostage negotiation principles were established in 1972 when then-NYPD 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.

The first Hostage Negotiation Teams (HNTs) were often created as elements of Special Weapons and Tactics (SWAT) Teams and merely created a diversion while SWAT deployed. In modern usage, while sometimes acting independently, hostage negotiation teams are often deployed in conjunction with SWAT.

The FBI Crisis Negotiation Unit (which developed the Behavioral Change Stairway Model) and Singapore Police Force Crisis Negotiation Unit are examples of specialized units trained in these techniques.

One specific model developed by the FBI is the Behavioral Change Stairway Model. Police negotiators that follow this model work through the following stages in order

It is considered to be important to work through these steps in order, and not to try to effect behavioral change before rapport has been established.

...
Wikipedia