The New York City Police Department (NYPD), established in 1845, is the largest and one of the oldest municipal police forces in the United States, serving a city of approximately 8.5 million residents[4]. Originating from earlier forms of policing dating back to the Dutch era in 1625, the NYPD evolved from a patchwork of smaller forces into a unified, professional organization modeled on London's Metropolitan Police[1][2][3]. This transformation included the replacement of the inadequate night watch system and the consolidation of 18 smaller departments in 1898 following the city's expansion to include Brooklyn[1][2]. The NYPD’s core mission is to protect constitutional rights while ensuring public safety across a vast urban landscape, with responsibilities spanning law enforcement, crime investigation, traffic management, counterterrorism, and emergency response[4][5]. Its structure is hierarchical, led by a police commissioner and supported by deputy commissioners overseeing specific bureaus such as Patrol Services, Detective, Transit, and Counterterrorism[5]. The department operates 78 precincts, 12 transit districts, and nine police service areas, reflecting a broad operational scope that includes protecting the subway system's millions of daily riders and public housing residents[4]. Historically, the NYPD has undergone significant reforms and modernization efforts, notably under leaders like Theodore Roosevelt in the late 19th century and through ongoing professionalization in the 20th century[1][3]. The department has also embraced community policing since the early 1990s, balancing rapid response with improved police-community relations[2]. Technologically, the NYPD has integrated innovations such as early computing in the 1980s to enhance operations[8]. The department has achieved remarkable crime reductions in recent decades, positioning New York City as one of the safest major U.S. cities[4]. Notably, the NYPD played a critical role during and after the 9/11 attacks, with officers among the casualties and the