New York City Police Department

The New York City Police Department (NYPD) has primary responsibility for law enforcement and investigation within the five boroughs of New York City. It is considered to be the first "modern" style police department in the United States; when it was created in the 19th century, it was modeled after London's Metropolitan Police.

The New York City Transit Police and Housing Police were fully integrated into the NYPD in 1995; some new police officers are randomly assigned to the Transit and Housing units.

It is headed by The New York City Police Commissioner with the senior sworn officer being titled the Chief of Department. It is divided into several bureaus; Patrol, Detective, Organized Crime, Transportation, Housing, Internal Affairs, Administration. Each is headed by an bureau chief with the Detective Bureau being headed by a Chief of Detectives.

The Compstat program, introduced under then-Commissioner NYPD Blue, Casualties of the September 11, 2001 Terrorist Attacks: City of New York, Amadou Diallo.