Does Enforcing the Fourth Amendment Increase Gun Violence?

The New York Post reports that the "number of New Yorkers struck by bullets" was 9 percent higher in the four weeks following U.S. District Judge Shira Scheindlin's August 13 ruling against the NYPD's stop-and-frisk program than in the same period last year. Total shooting incidents were up 13 percent. The Post implausibly presents these numbers as evidence that Scheindlin's decision had an immediate impact on gun violence.

Scheindlin did not say police could no longer stop someone they reasonably suspect of involvement in criminal activity or that they could no longer frisk someone they reasonably suspect is armed. Instead she concluded that New York cops often stop and frisk people without reasonable suspicion and ordered various reforms, to be implemented under the oversight of an independent monitor, aimed at making such unconstitutional encounters less common. If these reforms work, they will ultimately make cops less inclined to stop and frisk people, and perhaps the ruling itself had such an effect. (The Post does not present data on stops before and after Scheindlin's ruling.) But it seems unlikely that a significant number of people read Scheindlin's ruling on August 13 and decided to carry a gun the following day, as the Post implies happened by citing a shooting that occurred on August 14.

Furthermore, the premise that shootings rise when street stops fall is belied by crime data for 2013, which show New York's murder rate continuing to drop despite a big decrease in the number of stops during the second quarter. Seeking to explain that inconvenient conjunction, police commanders interviewed by The New York Times in June cited "what they say is the long half-life of the deterrent effect of stop-and-frisk, saying that criminals may decide to leave their guns at home because they have been stopped in the past, even if the odds of a stop have decreased in recent months." If so, why would criminals respond to Scheindlin's ruling with the alacrity suggested by the Post?

But let's say the Post is right: When Scheindlin criticized the NYPD for tolerating unconstitutional seizures and searches, she increased the likelihood that the average triigger-happy thug would carry a gun during the next four weeks. How exactly did that work? Jorge Alvarez, a Harlem resident who was shot in the legs the day after Scheindlin's ruling when he was "caught in the crossfire between two drug gangs," offers one possible explanation:

They have to get illegal guns off the street. The only way to do that, besides stopping the sale of guns, is stop-and-frisk. If they can't check people, they're not going to find guns.

That theory might make sense if police actually seized guns during street stops, but they rarely do. As the number of stops grew from about 100,000 in Michael Bloomberg's first year as mayor to almost 700,000 in 2011, the share of stops yielding guns fell from 0.38 percent (one gun per 266 stops) to 0.033 percent (one gun per 3,000 stops). Even when police frisk someone they stop, supposedly based on a reasonable suspicion that he is armed, they find a weapon of any kind only 2 percent of the time. So the crime-control rationale for New York's stop-and-frisk program cannot plausibly be based on the number of guns the police are seizing. Rather, as the police commanders' reference to "the deterrent effect of stop-and-frisk" indicates, the strategy is supposed to reduce shootings by making violence-prone men think twice before carrying a gun. Since deterrence is the name of the game, the failure to find guns is a sign of success, as Bloomberg has explained. Ideally, according to this way of thinking, cops would never find guns on the people they frisk.

The problem, of course, is that reasonable suspicion should mean a significant proportion of the people who are patted down for weapons turn out to be armed. Thus the city's practical argument for promiscuous street stops has always been at odds with its constitutional defense of the strategy. As Scheindlin noted in her decision, it is perfectly possible for a police tactic to be unconstitutional yet effective. Summary execution of jaywalkers no doubt would deter jaywalking, and random, warrantless searches of people' homes might very well discourage illegal drug use. But that does not mean such policies would be consistent with the Fifth and Fourth amendments. Likewise, claiming the NYPD's stop-and-frisk program works as intended, deterring gun carrying by creating a general fear that anyone can be searched at any time for any reason or no reason at all, hardly proves it is constitutional. Quite the opposite.