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, when it was created back in the 19th century, and modeled after London's Scotland Yard.
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.
The Compstat program, introduced under then-Commissioner Bill Bratton in the 1990s, uses statistics about crime rates and arrests to evaluate police precincts and commands. As of June 2003, there are charges that the statistics have been falsified to make the department look better.
The size of the force has fluctuated, depending on crime rates, politics, and available funding. In November 2003, there were about 36,000 uniformed officers.