My favorite top cop in the nation has just bowed out. Bill Bratton, arguably America’s most effective big-city police chief, retired in September, ending one of the most successful careers in law enforcement in the nation’s history. Bratton’s record wherever he served, including Boston, Los Angeles and two stints in New York City, was impressive. Crime of all sorts, especially violent crime, fell precipitously in each one on his watch.

About the time Bratton was wrapping up his last day on the job in New York, Washington, D.C.’s police chief, Cathy Lanier, was starting a new job in the private sector, as head of security for the National Football League. Almost a decade ago, she took control of a department that was viewed as largely dysfunctional and remade it, strengthening ties between officers and the community they serve. Crime fell substantially during her tenure.

Their departures are only two among a slew of chiefs leaving their posts in recent months, including Dallas’ David Brown. Most of them, however, were not voluntary. In Baton Rouge, Chicago, Cincinnati, Oakland, Portland, Ore., San Diego and San Francisco, among others, the chiefs were fired or pushed out. In Bay St. Louis, Miss., the chief was suspended as part of an internal investigation and immediately committed suicide.

We live in a time of intense concern about the relations between police and their communities. Every day, the media is boiling over with horrifying stories about violent crime, unwarranted police attacks on citizens -- usually minorities and often very young -- and recent suicidal counterattacks against the police. If you had no context, you’d think the country was coming apart at the seams. But it isn’t. The rate of violent crime is about half what it was 25 years ago, including fatalities among on-duty police. True, the rate has spiked in some cities, notably Chicago and Milwaukee, but it remains steady in many others. The number of murders this year in Chicago, our third-largest city, is greater than that in Los Angeles and New York, the two largest, put together.

What does seem different is the level of police misconduct. Reliable statistics are hard to come by, but a study funded by the U.S. Justice Department covering part of 2005 through 2011 showed that on average police officers are arrested around 1,100 times a year, most often for crimes involving assault, drunken driving and sexual misconduct, with almost 60 percent occurring off-duty. These numbers are worrisome, but taken in context, they’re not startling. The Justice Department estimates there are somewhere around 750,000 state and local law enforcement officers across the country, so their crime rate is minuscule compared with society at large.

Still, the seemingly daily scenes of police shooting unarmed civilians, often without a warranted reason, are deeply disturbing. They breed more anger, increased resentment and a widening gap between cops and their communities. “It’s not a police issue, it’s a society issue,” Chicago Police Superintendent Eddie Johnson told reporters in September. “People without hope do these kinds of things.” 

That may be true, but the sudden spike in crime in cities like Baltimore, Chicago, Memphis and Milwaukee -- and the preponderance of police misconduct in many other places -- demands a hard look not only at police leadership and management systems, but also the quality of our entire criminal justice system.

Justice Department investigations in Baltimore and other cities over the past several years have revealed inadequate or even nonexistent early intervention systems for identifying officers at high risk for serious misbehavior. One study estimated that 22 percent of officers who’d been arrested for misconduct previously had been defendants in federal civil rights cases. More than half the arrested officers were allowed to resign voluntarily and move on to another police force. There is little coordination among state and local agencies and almost no federal oversight, so problem cops can wander from one job to another. In one infamous case, an officer in a small Oregon town was dismissed from the force for kissing a 10-year-old girl on the mouth, but was hired only three months later as the chief in a town in Kansas -- even though the court in Oregon had ordered that he never serve as a policeman again. 

For cops, the frustrations focus on the waves of illegal firearms flowing into cities and what can be a nonsensical pattern of sentencing in which officers find themselves arresting the same people over and over again, often for serious crimes. Meanwhile, marginal offenders are shipped off to prison, sticking taxpayers with big bills for minimal results.

City and county councils, state legislatures and the U.S. Congress all are eager to pass reforms, which worries chiefs like New York’s Bratton: “There are police reformers from outside the profession who think that changing police culture is a matter of passing regulations, establishing oversight bodies and more or less legislating a new order,” he wrote in a farewell column in The New York Times. “It is not. Such oversight usually has only marginal impact. What changes police culture is leadership from within.”

Lanier is more forceful in her frustration, particularly about the unwillingness of federal agencies to monitor suspects. That’s a level of government with whom the chief must work since D.C.’s the nation’s capital. “The criminal justice system in this city is broken. It is beyond broken,” she told The Washington Post before she stepped down. “Where the hell is the outrage?”

Both retiring chiefs make good points. Reforms are clearly needed -- in the courts, in the tracking of police behavior and in coordination between agencies at all levels. But in the end, meaningful reform will have to come from the cops themselves. The good news is that, with so many new chiefs on the job in cities across the country, it’s a prime opportunity to start those conversations now.