As a figure of popular mythology, the American police officer never stood taller than in the patriotic aftermath of 9/11. In sharp contrast, the prototypical cop has taken a public pounding in recent months. A cascade of bad behavior — and, in some cases, charges of criminal behavior — has led not only to questions about proper policing in poor African-American neighborhoods but also to larger questions about the perpetual poverty and social isolation of many of those neighborhoods and why more progress hasn't been made.

Fairly or unfairly, the police officer patrolling those streets has become a daily reminder to residents that they and their communities have been left far, far behind. That millions of black Americans have vaulted into the mainstream economy and culture, and that the nation has twice elected a black president, only sharpens the sense of neglect and despair on the most desperate blocks of West Baltimore, South Chicago, North Philadelphia and other isolated urban districts.

For police officers, the irony cuts deep; high crime rates dictate that these are the places where cops are most needed — but, as it often seems, these are also the places where cops are least wanted or appreciated. One reason is that good community policing in tough neighborhoods is very hard to do. These are places where criminals (and many who "pose" as criminals) gain respect through intimidation or violence. But a police department that answers in kind becomes just another street gang. Good community policing defies human nature; it responds to violence and intimidation with reasonable restraint and a capacity for understanding. Even well-trained officers often lack the extraordinary patience and temperament required.

"They give you the tools to answer violence with an equal amount of force," a Minneapolis officer told us last week. "But that doesn't mean it's the right answer."

It clearly wasn't the right answer in Cleveland, where an officer jumped onto the hood of a car after a chase and fired 49 shots into the windshield. An unarmed black couple died. The white officer was acquitted last week because a judge couldn't determine whether those shots or 88 other shots from 12 other cops had killed the couple.

President Obama was wise this month to order a partial demilitarization of local police forces by denying them some of the equipment it takes for them to operate as overly aggressive occupation armies. And, on a smaller scale, a federal grand jury may have sent a similar message by indicting Minneapolis patrol officer Michael Griffin on nine counts of assault, signaling that he may lack the proper temperament to carry a badge. Griffin pleaded not guilty to charges that he beat four men in 2010 and 2011 and lied about it during civil suits they filed against him.

As a concept, community policing dates back to the 1820s in London, but it wasn't embraced in big U.S. cities until the 1980s. Its proactive approach and reliance on police-citizen partnerships requires a high level of mutual trust, something that's still obviously lacking in impoverished black neighborhoods and among the officers patrolling them.

Mutual trust seems no problem in more prosperous zones, however. The police officer's tattered image got a complete makeover last week in one such corner of Minneapolis. More than 250 neighbors jammed into a riverfront cafe near St. Anthony Main to celebrate their local beat cop, to heap praise on the Police Department and to fork over $9,000 in private contributions toward supporting their neighborhood police substation.

The atmosphere was festive. It was the 15th annual "keep the beat" event, allowing cops and residents to mingle and trade gestures of mutual appreciation. "This relationship we have with you is important to us," Kathy Waite, commander of the Second Precinct, told the crowd. "When you see us on the street, stop and say hi, or give us a wave."

If only that kind of relationship could flourish in every urban neighborhood, no matter income or race. It's something for all sides to work on, starting now. No city should have to wait for the Justice Department to impose constraints on local police, as happened in Cleveland last week. But genuine, lasting improvement will come only when both sides — police and community — understand that they must change.