Some Effects of an Increase in Police Manpower in the 20th Precinct of New York City
A study of the change in crime patterns in New York City's 20th Precinct after a 40 percent increase in police manpower in 1966. The study analyzes ten crime types including robbery, grand larceny, burglary, felonious assault, auto theft, total felonies, and total misdemeanors. After correcting data for seasonal variations, the author compared changes in 20th Precinct crime rates with changes in selected control precincts where there had been no manpower increase. The number of outside or street-visible robberies was found to be 33 percent lower than otherwise expected, while both outside grand larceny and auto theft were 49 percent lower. Misdemeanor rates were not affected significantly. During the experiment, there was some increase in major crime types in the Central Park district bordering the 20th Precinct on the east, but generally by an amount less than the crime decrease in the 20th Precinct.