Since 2005 the city has had the lowest crime rate among the 25 largest U.S. cities, having become significantly safer after a spike in crime in the 1980s and early 1990s from the crack epidemic that affected many neighborhoods. By 2002, New York City had about the same crime rate as Provo, Utah and was ranked 197th in crime among the 216 U.S. cities with populations greater than 100,000. Violent crime in New York City decreased more than 75% from 1993 to 2005 and continued decreasing during periods when the nation as a whole saw increases. In 2005 the homicide rate was at its lowest level since 1966, and in 2007 the city recorded fewer than 500 homicides for the first time ever since crime statistics were first published in 1963. 95.1% of all murder victims and 95.9% of all shooting victims in New York City are black or Hispanic.
Sociologists and criminologists have not reached consensus on what explains the dramatic decrease in the city's crime rate. Some attribute the phenomenon to new tactics used by the New York City Police Department, including its use of CompStat and the broken windows theory. Others cite the end of the crack epidemic and demographic changes.
Organized crime has long been associated with New York City, beginning with the Forty Thieves and the Roach Guards in the Five Points in the 1820s. The 20th century saw a rise in the Mafia dominated by the Five Families and they still are the largest and most powerful criminal organization in the city.Gangs including the Black Spades also grew in the late 20th century. As early as 1850, New York City recorded more than 200 gang wars fought largely by youth gangs. The most prominent gangs in New York City today are the Bloods, Crips, Latin Kings, and MS-13.