How much did Bill Bratton's policing change New York?

NYPD Commissioner Bill Bratton announced his resignation on Tuesday, marking the end of a long and controversial career. 

Longtime New York City police commissioner Bill Bratton announced on Tuesday that he would resign from the position next month, marking the end of an era for the New York Police Department. 

Commissioner Bratton, perhaps known best for promoting "broken windows" policing strategies in the 1990s, is a somewhat divisive figure in law enforcement. Some criminologists say his revolutionary techniques were largely responsible for the sharp decline in New York's crime rate: Violence peaked in 1990, four years before Bratton first became commissioner, with 30.7 killings for every 100,000 people in the city. Last year, there were only 4.1 homicides per 100,000 people. 

Others argue that broken windows policing – a theory introduced in 1982 by criminologists James Q. Wilson and George L. Kelling, which centers on the idea that if nothing is done about small crimes in a community, they can lead to more severe offenses – has in fact paved the way for techniques such as stop-and-frisk and zero-tolerance policing, which have worsened relationships between police and low-income and minority communities. 

A number of academics over the years have examined the role of broken windows policing in reducing New York's crime, as well as other strategies introduced during Bratton's time as commissioner, but a consensus has yet to be reached. One of the most recent reports, published in June by the city's Department of Investigation, found no correlation between cracking down on low-level quality-of-life offenses, such as public urination, and a decrease in the felony crime rate. The NYPD responded that the report was "deeply flawed" and should have examined data going back to 1990. 

Some criminologists suggest that a number of other factors may have played a role in the drop in crime. In a 2006 article published in the University of Chicago law review, political theorist Bernard Harcourt and economist Jens Ludwig argue that the decrease in crime throughout the 1990s and early 2000s paralleled the natural decline in the crack epidemic; other critics have suggested that the lowered crime rates could be at least partially attributed to a decline in unemployment around the same time. 

Criminologist Franklin Zimring, a professor at the University of California at Berkeley and author of "The City That Became Safe: New York's Lessons for Urban Crime and Its Control," has argued that about half of the crime drop was probably due to changes in policing under Bratton's leadership, such as a 41 percent increase in the number of officers between 1990 and 1999. 

"Bratton has been an effective and innovative police administrator throughout his career, and surprisingly flexible in his priorities and concerns," Professor Zimring tells The Christian Science Monitor in an email. 

One controversial program introduced under Bratton's leadership in 1994 is CompStat – short for computerized or comparative statistics – which uses data collected by officers to determine where and how to police in the future. Though one recent analysis by the Brennan Center for Justice found that the system, which has since been adopted by other police departments, reduced homicides nationally by 11 percent, critics of CompStat say the system encourages officers to make as many arrests as possible for the sake of data collection. 

Debates over the effectiveness of certain policing strategies in reducing crime "will never be resolved," says David Kennedy, the director of the National Network for Safe Communities at John Jay College of Criminal Justice in New York, in a phone interview with the Monitor. 

But regardless of what exactly caused the decline in crime between 1990 and today, Mr. Kennedy says, "The two big things that Bratton's career represents are a really transformative change in police attitude and culture – to say the police will actually produce public safety, they will not simply be reactive – and then a really steadily evolving understanding of how police can do that." 

From his start in New York as chief of the New York City Transit Police in 1990, throughout his promotion to commissioner in 1994, his appointment to Los Angeles Police Department chief of police in 2002, and his eventual return to New York as commissioner in 2013, Bratton has demonstrated a "steady commitment to actually producing crime reductions that happened in all those places," as well as a shifting focus on how best to improve community-police relations, Kennedy says.

He cites as examples reductions in stops, a shift away from stop-and-frisk, and a relaunch of community policing since Bratton's return to New York in 2013.

"I think what’s remarkable about Bratton's career is that he has been transformative in every agency where he has led, and that his sense of what was appropriate for policing has changed steadily along the way," Kennedy says. Though Bratton is, of course, "not perfect," he adds, "that trajectory of leadership, I think, is unparalleled."