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.

Over the years, the tactic would become more prevalent — and common far beyond New York — as the public outcry over its use rose. By 2011, the New York Police Department that many cities tried to copy conducted 685,724 stops, the peak before a bitter legal tussle and a new mayoral race would begin to scale back the practice:

This picture comes from a New York Civil Liberties Union report released Wednesday that the group is framing as a comprehensive account of stop-and-frisk during the Bloomberg years. During the mayor's 12-year tenure, police department data show that officers made more than 5 million stops, a quarter of them of young black men who made up just 1.9 percent of the city's population.

The NYCLU report documents the racial imbalance that has made the policy so divisive in New York and other cities where the practice has contributed to animosity between minority communities and law enforcement. But the ACLU accounting also points to other data that undermine the rationale for stop-and-frisk: It yielded few weapons when officials justified the policy as a way to reduce shootings and recover guns; in more than 5 million stops, police recovered a gun less than 0.02 percent of the time. And as the NYPD ramped up the number of stops, shootings and murders in the city did not appear to correspondingly decline:



NYCLU

There are so many factors that influence the rise and fall of crime trends, and police tactics represent just one. But to the extent that supporters have argued that stop-and-frisk makes cities safer, the above chart is a fair rebuttal.

Since new New York Mayor Bill de Blasio ran — and won — on reforming the practice, the city has reached a legal settlement to work with a court-appointed monitor on revising the policy (the city's police unions were recently shot down in the their attempt to scuttle it). Now that police tactics in minority communities are under national scrutiny once again, this data reaffirms that some of the tactics that antagonize residents may not be all that valuable anyway.