Wonkblog: 12 years of data from New York City suggest stop-and-frisk wasn't that effective

In 2002, when Michael Bloomberg first took office as mayor of New York City, the controversial law enforcement policy known as "stop-and-frisk" led to 97,296 encounters on the city's street. Police stopped -- and sometimes frisked -- pedestrians on any number of suspicious grounds: Their movements seemed "furtive," as if they were casing a victim, acting as a lookout, or selling drugs. They seemed to be carrying a suspicious object, or sporting a suspicious bulge.