Andrew G. Nelson Books in Order

The Emergency Service Unit (ESU) is part of the Special Operations Division of the New York City Police Department and was formed in 1930. The unit provides specialized police tactical support and advanced equipment to other NYPD units. Members of ESU are cross-trained in multiple disciplines for Special Weapons and Tactics, barricaded subjects, hostage rescue missions, high risk search warrants, technical rescue and emergency medical service alongside law enforcement support operations. NYPD ESU is generally considered to be the oldest police SWAT unit in the United States.