by Richard Moran

About the author: Richard Moran is a professor of sociology and criminology at Mount Holyoke College in South Hadley, Massachusetts.

New York Mayor Rudolph Giuliani and his former police commissioner, William Bratton, have seized credit for the abrupt drop in New York City’s murder rate. They claim that their policing strategy of “zero tolerance” for minor lawbreakers like squeegee men has made New York safe again; now other cities, including Washington, D.C., are heralding their tactics as the best way to combat crime.

No Correlation Between Police and Declining Murder Rates

But while the argument that the police deserve all the credit for the drop in homicides sounds plausible, no solid scientific evidence supports their claims of omnipotence. Indeed, the weight of the evidence suggests that...