By Eric Tucker, Associated Press

WASHINGTON (AP) — To supporters, zero-tolerance policing has long represented a logical crime-fighting approach: Crack down on minor infractions before they mushroom into more serious and disruptive violence.

But a scathing federal government report (pdf) on the Baltimore Police Department suggests the costs of that strategy outweigh any reduction in crime. The Justice Department report released Wednesday blames zero-tolerance policing for a legacy of discriminatory law enforcement in which black residents are disproportionately stopped and searched without cause.

"The police department's 'zero tolerance' street enforcement strategy became a quest to produce large numbers of enforcement actions — pedestrian stops in particular — often without enough consideration of their limited impact on solving crime and their caustic damage to community relationships," Vanita Gupta, head of the Justice Department's civil rights division, said at a news conference.

The conclusion forcefully rejects a strategy critics condemn as unduly harsh and one that has fallen out of favor in some of the same cities, including Baltimore, where it was developed and regularly employed. The report also revives a public dialogue that surfaced repeatedly on the presidential campaign trail, particularly as former Baltimore Mayor Martin O'Malley, who still defends the zero-tolerance policy, sought the Democratic nomination.

Over the years, the strategy has divided academics and police and government officials.

"It reflects a debate that's been going on for quite a while, and to the extent that we can find the government acknowledging those costs and downsides, it's about time," said David Harris, a University of Pittsburgh law professor who specializes in police policy and conduct.

Zero-tolerance emerged as a popular strategy in Baltimore more than 15 years ago. Its effectiveness was touted by O'Malley, who was elected in 1999 at a time when homicides were regularly topping 300 a year. A similar "broken windows" philosophy was promoted even earlier in New York City and elsewhere, with the theory that policing petty offenses, such as graffiti and public urination, can protect against more serious crimes.

In Baltimore, officials advocated "stop and frisk" policies and cracked down on public drunkenness, disorderly conduct and similar offenses. In 2005, more than 100,000 people were arrested — roughly one sixth of the city's population.

The city's homicides remained below 300 for the next decade, but complaints swiftly emerged that citizens were being targeted for misdemeanor offenses. A grand jury concluded that too many arrests in black neighborhoods lacked merit, and the city paid $870,000 to settle the NAACP's lawsuit on behalf of people who said they were illegally arrested.

Last year, some blamed the zero-tolerance approach for the death of Freddie Gray, a 25-year-old black man whose neck was broken in the back of a police van after he was arrested while trying to flee an officer patrolling his neighborhood.

O'Malley, who became governor of Maryland in January 2007, repeatedly defended zero-tolerance policing on the presidential campaign trail. In one debate, he noted that he was elected mayor at a time when the city was "burying over 300 young, poor black men every single year."

"We were able to save a lot of lives doing things that actually worked to improve police and community relations," O'Malley said.

He defended the approach again Wednesday, saying the report did not account for improvements under his watch, including "historic reductions in violent crime." Though enforcement intensified as the police worked to shut down open-air drug markets, arrests declined as violent crime went down, he said.

"Improving community trust and reducing violent crime are mutually reinforcing actions, not an either/or proposition," he said in a statement.

Current police leaders in Baltimore have disavowed zero-tolerance policing, but the legacy remains in the persistent stops and searches that yield neither citations nor arrests, the Justice Department said. According to the report, 410 people were stopped at least 10 times from 2010 to 2015. One black man was stopped 30 times in less than four years and he was never charged.

"Many supervisors who were inculcated in the era of zero tolerance continue to focus on the raw number of officers' stops and arrests, rather than more nuanced measures of performance," the report said.

Eugene O'Donnell, a former New York Police Department officer and professor at the John Jay College of Criminal Justice, said the report's conclusions failed to take into account the difficult realities of being a police officer in Baltimore. Even zero-tolerance policing, he said, was rooted in a goal of trying to combat crime in a "city that is really in a bad place."

"It was some effort to try to staunch the bleeding, try to respond to some community concerns, try to go after street corner after street corner after street corner where people are congregating and businesses are being driven out and residents are up in arms," he said.

Harris, of Pitt Law, said it was clear that zero-tolerance policing was insufficiently flexible and nuanced, even if it has contributed to a drop in crime.

"I'm sure it contributes in some way. The question is, does it contribute as much as a better strategy would?" he asked. "If you lock up everybody for anything, you're inevitably going to get some bad guys off the street. But you're going to take a lot of people who are not so bad and treat them as bad guys."

To Learn More:

Investigation of the Baltimore City Police Department (U.S. Department of Justice, Civil Rights Division) (pdf)

Strong Racial Bias by Baltimore Police Detailed in New Justice Dept. Report (by Richard A. Oppel Jr., Sheryl Gay Stolberg and Matt Apuzzo, New York Times)