The Justice Department has criticized a string of police departments nationwide for unfairly targeting blacks, but in its report on the Baltimore police, issued Wednesday, it used its most scathing language to date to denounce the zero-tolerance policing approach that has spread from New York to many departments big and small.

The broken-windows style of policing that New York evangelized with particular fervor during William J. Bratton’s first term as police commissioner is increasingly viewed more as a source of tensions with minority communities than as a successful crime-fighting strategy.

Taking up too much space on a park bench in New York. Spitting in public in Minneapolis. Moving household goods at night in Atlanta. Focusing on small violations to prevent bigger crimes has grown into a cornerstone of policing over recent decades.

But the Justice Department found that critical elements of that approach led to a breakdown in police-community relations in Baltimore and prompted a frenzy of unconstitutional policing aimed at African-Americans that was more about racking up statistics than reducing violent crime.

Baltimore’s “pattern of making unconstitutional stops, searches and arrests arises from its long-standing reliance on ‘zero tolerance’ street enforcement, which encourages officers to make large numbers of stops, searches and arrests for minor, highly discretionary offenses,” the report said. “These practices led to repeated violations of the constitutional and statutory rights, further eroding the community’s trust in the police.”

In an interview, Bratton said that the excesses of the Baltimore police should not discredit an approach to policing that he argued, far from being outdated or in disrepute, remained “the fundamental principle on which police operate.”

He distinguished between his policing approach, which requires officers to confront disorderly behavior but not necessarily to make arrests, and a zero-tolerance approach that measures success by arrest figures.

Bratton said the key was to adjust the level of police enforcement based on the security of the city. He noted that in recent years, as public safety improved, the number of arrests and police stops in New York dropped.

“We don’t do zero-tolerance policing,” he said, adding that he took “umbrage” at the Justice Department’s suggestion that zero-tolerance policing had migrated from New York to Baltimore and elsewhere. “Since we didn’t apply it,” Bratton said, “how did it migrate out of New York?”

Departments across the country, including those in Minneapolis; Atlanta; New York; and Tampa, Fla., have rolled back no-holds-barred enforcement of laws that criminalize minor offenses like spitting, riding bicycles on sidewalks, panhandling and public drinking.

The approach grew out of the war on drugs in the 1990s and record levels of murders, criminologists say, as departments sought to use renewed vigor by patrol officers to prevent major crimes.

In practice, however, data from police departments around the country shows that officers using the zero-tolerance strategy focused their arrests on African-American men in poor neighborhoods, while ignoring the same offenses in wealthier white neighborhoods.

One study, for example, showed that from 2008 to 2011, New York police officers issued eight citations for riding bicycles on sidewalks in Park Slope, a predominantly white Brooklyn neighborhood, but 2,050 in nearby Bedford-Stuyvesant, which is primarily African-American and Latino.

“A whole generation of police officers has come up under this approach: ‘Arrest. Arrest. Arrest,’” said David A. Harris, a professor and expert in police accountability at the University of Pittsburgh School of Law. He said the federal government’s denunciation “might signify a kind of turning point in law enforcement.”

Others pointed out, however, that the practice is standard in hundreds of police forces across the nation and that officers often win awards and promotions based on the number of arrests they make, including for minor offenses.

On Wednesday, Vanita Gupta, the head of the Civil Rights Division of the Justice Department, said the Baltimore police had pursued “a quest to produce large numbers of enforcement actions, pedestrian stops in particular,” which created “caustic damage to community relationships.”

Gupta added that even as the idea was discredited, “many in the BPD continue to follow this strategy.”

While some police officials have credited broken-windows policing with the large drops in crime nationally since the 1990s, a number of academic studies have questioned its effectiveness, and some officers have blamed the practice for the lack of public cooperation they receive in trying to solve violent crimes.

“We’ve been spending the past two decades trying to prove something, but there’s zero evidence for its efficacy,” said Michael A. Wood Jr., a former Baltimore police sergeant who now advocates police reform.

The frequency with which police officers — from Seattle to Oakland, Calif.; from Ferguson, Mo., to Philadelphia; and now in Baltimore — have been found to have infringed on the constitutional rights of citizens has led some police leaders to reject the practice in favor of community-based policing.

“The dilemma for police chiefs is how do you impact crime in high-crime neighborhoods without the overreach of violating the rights of people who have done nothing wrong,” said Chuck Wexler, the executive director of the Police Executive Research Forum, an organization that provides technical assistance to law enforcement agencies.

Ronal Serpas, who has been a police chief in New Orleans; Nashville, Tenn.; and Washington state, said that zero-tolerance policing had been losing adherents among chiefs for years, even before the 2014 riots in Ferguson, which were prompted by the fatal police shooting of Michael Brown.

Serpas said that police chiefs during the 1990s had imitated New York City’s broken-windows strategy under Bratton by intensifying efforts on low-level crime enforcement.

“Those policing strategies became a beast that fed itself,” Serpas said, noting that the rise in stop-and-frisks, arrests and tickets had become increasingly burdensome and intrusive. “In the years, we found out that we lost these people whose kids started getting caught up in these dragnets.”

In New York, the Police Department’s crime-fighting strategy had grown increasingly reliant on a particular component of broken-windows policing: the investigative stop, often called “stop, question and frisk.”

But police data showed that officers rarely found any evidence of criminality. In one precinct, only 4 percent of the stops resulted in an arrest or summons. In Brownsville, a predominantly African-American neighborhood of Brooklyn, young black men were stopped so often on their way home after school that members of a high-school football team began carrying their helmets home with them so the police would view them with less suspicion.

By the time Shira A. Scheindlin, a federal judge, concluded in 2013 that the department’s policies had led to widespread constitutional violations, the police commissioner at the time, Raymond W. Kelly, had already begun abandoning the strategy.

And since Bratton’s return as commissioner under Mayor Bill de Blasio, he has signaled to officers that a warning for a minor infraction is sometimes preferable to handcuffs. Bratton has announced that he will resign in September to take a job in the private sector.

The New York City Council considered decriminalizing numerous petty offenses, including public urination and public drinking. But, facing stiff opposition from the Police Department, it softened the legislation this spring, and the law now leaves it up to officers to decide whether to treat petty offenses as criminal or civil matters.

In Atlanta, Kwanza Hall, a City Council member, introduced legislation this year that would decriminalize a series of low-level crimes — including spitting, panhandling, moving household goods at night and loitering around railroad tracks — that he said had been used to target African-Americans.

And in June 2015, the Minneapolis City Council repealed laws against lurking — an offense similar to loitering — and spitting in public after an ACLU report showed that African-Americans and Native Americans were nearly nine times more likely than whites to be arrested on minor offenses.

While officers are given wide discretion in whether to make arrests, issue tickets or ignore minor crimes, they are often ordered by sergeants and lieutenants to confront every violation they see, a practice that the Justice Department said was called “clearing streets” in Baltimore.

This often meant, according to the federal report, that the police confronted people hanging out outside shops, searching them and checking for open warrants, even though the officers lacked the legal authority to do so.

“Zero-tolerance policing was not keeping us safer,” said Sherrilyn Ifill, the president and director-counsel of the NAACP Legal Defense and Educational Fund, and a Baltimore resident. “It’s not rocket science. We knew that this was devastating.”

© 2016 The New York Times Company