Every day across America, police officers investigate murders, defuse domestic squabbles, and arrest dope dealers.

But training is just as important when officers come across a "real American" who is combative and refuses to defer to police authority – even if the alleged offense is relatively minor.

The arrest of Henry Louis Gates Jr., the prominent Harvard scholar, has brought the issue of race and policing literally from the heights of academic inquiry to a dramatic faceoff between a blue-collar Boston-area cop and one of the ivory tower's most recognizable black scholars.

But perhaps one of the core underlying issues in the incident is one of policing: Officers walk a thin line between staying safe and adhering to the Constitution – and straying over that line can have consequences, especially when it involves the black community.

"We have a lot of African-American males in this country who are tired of having to justify their existence on the white streets of America," says Lorie Fridell, a criminologist at the University of South Florida in Tampa. "And if the police don't acknowledge that, they're going to lose a future person who will call the police with information, they're going to lose the witness to a crime, they're going to lose the person on the jury who believes the police officer's story."

Lessons to be learned

What lessons, then, can be drawn from the July 16 altercation on Gates' front porch on Ware Street?

For average Americans, the case shows that it's never a good idea to get "lippy," as police officers say, during an investigation of any kind.

And for police officers, it isn't just having "thick skin," one of America's top cops says. It is to understand, at a procedural level, the deep trust Americans have in basic constitutional values.

"Any cop can deal with a robbery suspect, but show me the cop who can handle a real American," says former Seattle police chief Norm Stamper, quoting policing expert George Thompson. "That's someone, when you say, 'Roll down the window,' says, 'No,' or who meets you at the threshold at home and says, 'No, you can't come in. Show me your warrant.' "

"Americans are the beneficiaries of the incredible foresight and wisdom of our Founding Fathers, who over time created a Constitution that embeds these rights of freedom for Americans," he adds. "So when you come across a real American, how competent are you in carrying out your delicate and demanding and too-often dangerous job?"

What should have happened

In his view of the Gates case, which he has studied closely, Mr. Stamper suggests that Gates overreacted. But Cambridge Police Sgt. James Crowley also made a basic mistake: By becoming distracted by Gates's criticisms and protestations, some of which invoked race, his warnings to Gates to calm down fell short of their mark. And as other police officers arrived, Stamper reasons that it became more difficult for Crowley to back down in front of his peers.

"As soon as you give a warning twice, your authority is shot," Stamper says. "Then, you've approached this thing in precisely the opposite way of how you should have approached it."

The best practice, Stamper says, is called "verbal judo" – and it's an art of its own.

The trick is not to become offended that someone is challenging authority but to turn the argument back on the subject, Stamper says. Instead of making repeated warnings like, for example, "Roll down the window or else," an officer should start by saying, "If you're me right now, how would you resolve this situation?"

Simply by turning the focus back to the subject and listening often de-escalates the tension, and it can be surprisingly hard to do. If the situation still escalates, an officer can take more dramatic actions, if [legally justified], Stamper says.

But for all the Gates case's lessons, former police officer George Kirkham, now a professor at Florida State University, says that it's actually very unusual for a single individual to be arrested for disorderly conduct on their own front porch. After years of studying Florida arrest reports, in fact, Mr. Kirkham says it's the only one he's come across.

"Once we cross this Rubicon – we know this man lives here, he's presented his ID, and it's inconceivable that he would be there for any illegitimate purpose – the police officer doesn't get to have his feelings hurt," he says. "That's why this is larger than black and white, and it goes to basic constitutional rights that we all enjoy – black, white or brown – including the right to be in your own home and say what you want."

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