Rudy Giuliani’s reputation has suffered recently, but 30 years ago, he was “America’s mayor,” the New York crusader who beat back crime by operationalizing James Wilson and George Kelling’s “broken windows theory.” The idea is that taking minor crime seriously sends a message of intolerance for lawbreaking more generally. People shape up.

Under Giuliani, police targeted and prosecutors punished panhandling, subway turnstile-jumping, and other petty crime. By 1996, theft was down around 40%. Murders plummeted from 2,605 in 1990 to only 649 in 2001.