The United States Department of Justice (DOJ) has designated the Federal Bureau of Investigation (FBI) as the lead agency for crisis management of domestic terrorist incidents in the US. The Bureau has a variety of operational response capabilities, maintaining a number of specialized units at various locations though out the US.

When a threat or incident exceeds the capabilities of a local FBI field office, the FBI’s Critical Incident Response Group (CIRG) deploys the necessary resources to assist that office, and facilitates the FBI’s rapid response to, and management of the crisis incident. The CIRG is home to several of the FBI’s specialist units. It contains crisis managers, hostage negotiators, behaviorists, surveillance assets, agents, manages the Bureau’s Special Weapons and Tactics (SWAT) program, and the Bureau’s elite Hostage Rescue Team, or HRT.

The CIRG was established in 1994 as a separate field entity to integrate the tactical and investigative expertise needed for terrorist, and other critical incidents, that require an immediate law enforcement response. Some of these incidents may include terrorist activities, hostage takings, child abductions and other high-risk repetitive violent crimes. Other major incidents that may require their assistance include prison riots, bombings, air and train crashes, and natural disasters. Its personnel are on call 24 hours a day, seven days a week, to respond to crisis incidents.

The CIRG has three branches including: The Operations Support Branch, the Tactical Support Branch, and the National Center for the Analysis of Violent Crime. Each branch furnishes distinctive operational assistance and training to FBI field offices as well as state, local and international law enforcement agencies.