It's a Thursday night and East Flatbush is fuming. New York City police officers are stationed at every corner for miles along Church Ave., which is this Brooklyn neighborhood's main thoroughfare. Traffic clogs the street and two B35 buses crawl alongside weary evening commuters. Red and blue lights pierce the nighttime air. "They're here because they killed that boy," one black woman says to another in a West Indian accent. "I just hope all these kids stay safe." That boy was Kimani Gray, a 16-year-old who was shot and killed in the neighborhood last weekend, and the kids to whom the woman refers are his friends--and their friends, family, and many strangers--who showed up for four nights last week to protest his killing. Wednesday night made national headlines, because police officers clashed violently with vigil goers. Forty six people were arrested, and photos from the night look more like Birmingham than Brooklyn; swarms of officers pin screaming black men on the ground, or against the hood of a cop car. So on this night there's the anticipation of violence, but no signs of it. Instead, what's most visible is the sheer force of the NYPD. In addition to standing in groups of four at every corner, they're on the tops of buildings and in police cars, on motorcycles and horses. At one point a group of 20 or so mostly black folks--young, clearly angry--make their way down a Church Ave. sidewalk. They're followed by a few cameramen. One woman wears a black t-shirt with "RIP Kiki"--Gray's nickname--scrawled across the front in red writing. Uniformed officers jog alongside them clad in riot gear, with plastic handcuffs dangling from their blue cargo pants. "You officers sure you have enough guns to kill a few teenagers," one boy says mockingly to the police standing nearby. The group finally reaches the place where Gray was shot, a street corner now home to dozens of candles, cards, teddy bears and posters. "They're trying to murder us like they did Kiki," one woman yells. "We want justice." Moments like these are rare in New York City. Two decades removed from record homicide rates and the city's last race riot, these days there are few direct group confrontations with police. But there are many smaller ones. Day-to-day encounters on street corners, on trains, and in housing projects. Communities of color in this city have become the focus of intense daily scrutiny in every facet of their lives, and it seems like Kimani Gray's murder was a tipping point, an outpouring of fury at a police department that has systematically encroached on the physical space of so many for so long. The unrest comes at an appopriate moment. This week, a trial begins to determine the constitutionality of the police department's "Stop, Question, and Frisk" program. NYPD has made that the program a hallmark of its fight against violent crime and, specifically, of Mayor Michael Bloomberg's quest to get guns off the streets of New York City. But there is mounting evidence that the program relies on racial profiling. In 2011, 87 percent of those stopped by the NYPD were black or Latino. Guns were found in less than .02 percent of those stops. But while the courts determine the legality of the program, its cultural impact has been profound, according to its targets and critics. It's impacted everything from the way that some young men dress to the urgency with which they carry around legal documents. "I always make sure I have my ID on me," says Curtis Jackson, a 28-year-old black man who lives in Brownsville, which is also the epicenter of the department's stops. "I have nothing to hide, but I've been pulled over and searched, and so have my friends." Jackson says that he's changed his style of dress as he's gotten older in part because he was more likely to be stopped if he wears what he calls "urban gear." "It's like, am I targeted because of the clothes I wear?'" [[WATCH: BROWNSVILLE YOUTH TELL COLORLINES ABOUT THEIR RELATIONSHIP WITH NYPD]](http://colorlines.com/archives/2010/08/voices_from_brooklyn_racial_profi...) Rosa Squillacote works as a policy analyst at the Police Reform Organizing Project in New York City and has worked on two reports that look at the cultural impact of stop-and-frisk. "[Stop-and-frisk] creates a sense that if you go outside, you're being watched," she told me. "And not just watched, but you're putting yourself at risk for physical confrontation or fines." That, Squillacote says, is what is so profoundly troubling about a program that the NYPD has touted as central to its plan to reduce crime. "The right to travel freely is a constitutional right," she says. "To limit that is to violate someone's fundamental rights, and it means that you're also punishing an entire community so that people in that community won't trust the police." Distrust of the police is certainly nothing new in black and Latino communities, and it's the stark historical parallels that put many on edge. "During the era of Jim and Jane Crow, you had explicit policies that legislative bodies passed to make sure black folks were 'in their place,'" says Phillip Atiba Goff, a UCLA professor who works as the executive director of research for the Consortium of Police Leadership in Equity. "We fought hard to get rid of that, so now law enforcement's job is not to protect one class of people. Instead, we're seeing them as an occupying force." This occupation was on stark display in East Flatbush last week. In a city that has often promoted itself as a model for combating gun violence, here were the living, breathing examples of the dangerous trade off it purports to make: allow organized harassment of specific kinds of people in specific kinds of communities in order to feel like Bloomberg's New York is a safer, shinier place than its past. But as witnessed in Flatbush last week, those people and communities are increasingly refusing to play along.