To highlight the prevalence of broken-windows policing in other neighborhoods with high minority populations, members of the Police Reform Organizing Project patrolled Park Slope to hand out quality-of-life violations. Photographs courtesy PROP

On a nippy Sunday afternoon last month, about a dozen volunteers for the Police Reform Organizing Project (PROP) descended on Park Slope, Brooklyn. Zipped up against the chill, they were unassuming, anonymous. In three groups of four people (a few more arrived later), they patrolled the western perimeter of Prospect Park, stood guard by the Park Slope Food Co-Op, and walked the avenues of kingly row houses. They were scouring the streets for white people behaving badly—littering, spitting, jaywalking, biking on the sidewalk, carrying open containers of alcohol, letting their French bulldogs off the leash, or committing any other quality-of-life violations, as the city’s officials call them. The day’s action was part parable, part prank. PROP volunteers were to approach wrongdoers and flash a sheet of paper that looked like a summons. It was, in fact, a little pamphlet, and inside everything was explained: these are not police officers, this is not a real stop, and you have not been given a criminal summons, “although you very well might have if you were in a different neighborhood and a person of color.” As Bob Gangi, the white founder and director of PROP, told me, “We want to dramatize a point.”

Tanyanne Ball was the best at dramatizing the point. Ball is a small, polite woman with a bun of curly red hair and a Northern English accent. She worked as a police officer in the United Kingdom for two years, a job she is at pains to distinguish from its American counterpart. (British bobbies don’t carry firearms.) She lives in Park Slope, and the volunteers had gathered at her house beforehand for a training session, the turkey sandwiches circulating in her light-filled living room on the top floor of a converted brownstone. Ball seemed to have mastered the form of affable confrontation: as soon as she saw someone perpetrating a civic peccadillo, she would stride up and calmly, grinningly ask, “Are you aware that you have just committed a violation?”

Reactions varied. Some offenders stood politely, listened to the whole speech, expressed one of several variations on liberal piety (they were, after all, well-informed people), and then went briskly about their business. A well-dressed couple—man and woman—briefly stopped but grew resentful of this rude interruption in the name of politics. Halfway through an activist’s little lecture, the man snarled that this was taking longer than an actual ticket would have. Gangi, in one of the first stops of the day, launched his body in front of a bicyclist who was freewheeling down the sidewalk. The rider, a woman with a backpack, was incensed. Gangi presented his information—bikes couldn’t be ridden on sidewalks, certainly not by black or Hispanic people—but she refused to be placated. To each of his statistics, she replied, with bitter insistence, “Yes. Yes. I am perfectly aware of that. Now get out of my way.”

Although quality-of-life violations are against city law, they have been effectively decriminalized in places like Park Slope, where affluent couples push strollers down gleaming sidewalks and life pulses along to the gentle beat of white liberalism. If you jaywalk, it’s safe to assume that no cop will stop you and no penalty awaits you. But in the poorer, darker neighborhoods of New York, something as small as jaywalking can often lead to a ticket. The numbers on the PROP pamphlet are stark: about eighty-one per cent of the 7.3 million people who were charged with summons violations between 2001 and 2013 were black or Hispanic. Or, to zoom in a little, there were eight bicycle-on-the-sidewalk summonses in Park Slope between 2008 and 2011; in Bedford-Stuyvesant, there were two thousand and fifty.

This sort of enforcement is the cornerstone of broken-windows policing, a method rooted in the theory that cracking down on minor infractions can reduce the incidence of more serious crimes. (If people can jaywalk with impunity, what else might they try to get away with?) The method has been denounced in progressive quarters for its disproportionate and largely negative effect on low-income communities of color. In 2013, twenty per cent of the four hundred and fifty-eight thousand summonses issued in New York City were dismissed because the original tickets were either defective or deemed factually insufficient. But the practice persists. “You’re not going to find the scientific study that can support broken- windows one way or the other,” Bill Bratton, the city’s police commissioner, recently told Ken Auletta. “The evidence I rely on is what my eyes show me.”

Certain consequences, however, are clear. That ticket for jaywalking, if ignored, can result in an open warrant. A subsequent stop for jaywalking, or littering, or public urination, or an open container can lead to arrest. (In the case of Eric Garner, who had a history of selling untaxed cigarettes, such a stop led to his death by asphyxiation.) The offender is then exposed to a criminal-justice system that, in the view of Gangi and PROP—and the thousands who flooded the streets to protest the police killings of Garner, Michael Brown, and hundreds of other people of color—is racist.

Back in Brooklyn, the sun fell behind a bank of clouds; it was getting colder and the Park Slopers were becoming more possessive of their time. They marched, bent, down the avenues. Impatient smiles flashed across their faces as PROP volunteers tried to stop them. They could be any old street canvassers, pleading for a contribution or a signature. A handsome couple in their twenties, each bearing a bouquet of flowers, were kind enough to stop (they had jaywalked) as Ball explained to them the privilege that they had so thoughtlessly exercised. The man fidgeted, the woman blinked into the wind. “The inequality is ridiculous,” she said softly. “I don’t know anyone who has ever been harassed by the police.” They walked on.

“What they’re admitting is that they don’t know any people of color,” Shivani Manghnani, who had been posted at the Park Slope Food Co-Op, said as the couple moved out of earshot. By this point, we were standing outside the Barnes & Noble on Seventh Avenue. Someone peered through the glass and saw that there was an officer, in full N.Y.P.D. regalia, stationed inside, guarding the door of the bookstore. Ball, the most diplomatic of the group, went in to talk to him.

Their conversation began cordially enough—this was his day off; he was doing some freelance security work for the extra pay—and then Ball brought up the target of PROP’s demonstration. “What do you think about broken-windows policing?” she asked with sudden directness. His face hardened, then fell. “I don’t know. I never thought about it, to be honest with you,” he replied. She asked him whether he had ever given out a summons for jaywalking in this neighborhood. No, he said; he was usually stationed in Coney Island. Had he noticed a difference in how police behave in different neighborhoods? “Some police officers use a lot of discretion,” he said. Was he at all surprised to learn of the eight bicycle-on-sidewalk summonses? “To be honest, nothing really surprises me anymore,” he replied. The conversation was stiffly respectful; the guard was smiling weakly, clinging to his scruples. Between him and Ball lay a whole universe of prohibitions and protocols, the grand churning of systems. After a few minutes, there was nothing left to say. His thumb was tucked into his utility belt and his fingers drummed uneasily on the leather. A few inches away, nestled in its holster, was his gun.