Over the weekend New York Mayor Michael Bloomberg condemned critics of the NYPD's "stop and frisk" program, under which police detained supposedly suspicious people, overwhelmingly black and Hispanic, for questioning and/or pat-downs a record 684,330 times last year. "They sit there, and they pontificate and they complain," Bloomberg told reporters after speaking at the Greater Allen AME Cathedral in Queens on Sunday, referring to the New York Civil Liberties Union (NYCLU). "Our police officers put their lives on the line every single day." The implication—that respecting civil liberties endangers officers' lives and is therefore a luxury they cannot afford—is not exactly reassuring, especially coming from a man who implicitly concedes that the "reasonable suspicion" police are supposed to have when they stop someone is no more than a legal fiction used to justify a more or less random dragnet whose main value is not crime detection or weapon confiscation but deterrence.

Writing in The New York Times, the Manhattan Institute's Heather Mac Donald likewise defends the stop-and-frisk strategy based on its purported effectiveness. Since the early 1990s, she says, crime has declined faster in New York than in other big cities, and "only New York's policing revolution, which began in 1994 and seeks to prevent crime before it happens, explains the distinction." Mac Donald admits that "being stopped when you are innocent is an infuriating, humiliating experience" and suggests that "New York’s officers need to better explain to stop subjects why they were accosted." (Toward that end, the NYPD plans to supply its officers with "informational cards" that "provide a written description of the legal authority for such stops and a list of common reasons individuals are stopped by the police.") Mac Donald even allows that "if a more powerful method of deterring crime is developed, the N.Y.P.D. should and would adopt it." But "for now," she says, the NYPD should stick with the "assertive style of policing" that has allowed "New York’s most vulnerable residents" to "enjoy a freedom from assault unknown in any other big city." 

Bloomberg and Mac Donald both seem to think a policing strategy is justified if it reduces crime, but surely that is not the end of the analysis. One can imagine "a more powerful method of deterring crime" that even Mac Donald would reject because it entailed unacceptable violations of civil liberties: omnipresent, 1984-style surveillance, say, or summary execution of suspicious characters. Even if we assume, for the sake of argument, that stop and frisk is a crucial part of a "policing revolution" that is largely responsible for the big decline in crime the city has seen since 1994, that does not make it legal. In a federal class action lawsuit on behalf of innocent people stopped by the NYPD, the Center for Constitutional Rights (CCR) argues that New York cops routinely violate the Fourth Amendment by detaining and searching people without the "reasonable suspicion" the Supreme Court has said is necessary. The NYCLU's numbers support that argument, showing that stops, which are supposedly justified by a reasonable suspicion of criminal activity, result in a summons or arrest (including trumped-up pot busts) in just one out of 10 cases, while searches, supposedly justified by a reasonable suspicion that the target is armed, almost never turn up a weapon. In short, New York cops' suspicions do not seem very reasonable.

Routinely subjecting innocent people to the "infuriating, humiliating experience" of being stopped, interrogated, and frisked for no good reason may indeed have some deterrent value, as Bloomberg and Mac Donald claim. But that does not mean the practice is just or constitutional. As U.S. District Judge Shira Scheindlin emphasized in certifying the CCR class action, "suspicionless stops should never occur." It would be nice if the mayor of our largest city, who has admirably defended the religious freedom guaranteed by the First Amendment, at least paid lip service to the Fourth. Instead he displays what Scheindlen called a "cavalier attitude towards the prospect of a 'widespread practice of suspicionless stops,'" reflecting "a deeply troubling apathy towards New Yorkers' most fundamental constitutional rights."