"Walking while black" is an expression well known to Americans of color, meaning you're more likely to be seen as a troublemaker because of your skin color. And it's a concept that parents start talking to their kids about -- especially boys -- well before they're old enough to encounter problems.

Such talks took on greater urgency in the wake of the killing of an unarmed Florida teen, Trayvon Martin, by a neighborhood watch captain on Feb. 26. The shooting has sparked protest marches nationwide; one is set for 6 p.m. Thursday in Minneapolis, beginning at the University of Minnesota's Northrop Auditorium.

New details emerged this week in which the watch captain, George Zimmerman, alleges that Martin punched him and slammed his head into the concrete after he followed Martin. Regardless of how the case plays out, some parents are drilling their children on how to recognize if they are being racially profiled, and how to minimize the chance of putting themselves at risk.

The Rev. Devin Miller, who is helping to organize Thursday's event, advises his children and "all young people to carry yourself as you want to be seen. Once you carry yourself that way, it's not up to you to convince someone you're OK."

Black youths must be constantly on their guard, Miller said. His counsel to young people of color: "When someone tries to impose themselves on you, self-defense or self-preservation is the first test. The next is to call an adult or call the police."

Miller thinks the Florida case has incited intense reaction because "we're at a tipping point in our country in regards to treatment of African-American males, both academically and publicly. When you look at schools, the incarceration rate, all these things have culminated in what happened to Trayvon. The problem is when people look at it as a statistic and fail to look at the humanity of the individual."

At 79, Naima Richmond, part-time receptionist at the University of Minnesota's Urban Research and Outreach-Engagement Center in north Minneapolis , recalls four generations of "walking while black" parental warnings.

"Back in the '30s, I remember my mother telling my brothers not to say anything or resist," she said. "It was happening when I was young, and it's still happening. We become victims of something we're not responsible for."

What many children don't understand is that they may be perceived as a threat because of where they are, what they are wearing or simply their skin color.

Cynthia Smith, her two sons and three daughters live in the Regina neighborhood near Lake Nokomis in south Minneapolis. She says it breaks her heart to tell her children that they aren't necessarily safe, even if they've done nothing more threatening than walk the streets of their neighborhood. The instructions go like this: Keep your hands out of your pockets. Carry your ID at all times, and whatever you do, don't run.

"I have been telling my boys since they were 5 or 6 years old, because there were things they saw happen to older boys that I had to explain. They'd say 'Mom, why? They weren't doing anything.'"

Cedric Weatherspoon, a Minneapolis family therapist who works with many teens, including some in the correctional system, thinks that teens who live in the inner city, regardless of race, "get profiled in general," he said. "They get a bad rap. Whenever a bunch of teens congregate in the city, people assume something negative is going to happen. And if they are kids of color, well, that's an ongoing story."

Weatherspoon, who is black and the father of three, said that while growing up in the South he learned to "navigate through" instances when he felt he was being profiled.

"You just cooperate, you don't go into what's right or wrong at that time," he said. "You can have a conversation, but don't argue. On law enforcement's side, they have to make tough decisions sometimes, too."

When Weatherspoon talks with teens about racial profiling, he focuses on how it makes them feel.

"For some it gets to the point where they feel like they can't walk down the street," he said. "They can get very angry about it and wonder how they can go through life this way. I tell them to remember this one person does not represent everyone out there."

Fox News commentator Geraldo Rivera has been strongly criticized for his "blame the hoodie" statements in which he urged parents of black and Latino boys to prohibit their children from wearing hoodies because the popular sweatshirt style can make them look suspicious.

But members of the black congregation of the True Apostolic Assembly Church in southwest Minneapolis, mingling in front of the church after services last Sunday, were divided about their children's right to dress as they want and how, in their view, that might contribute to risk.

"When some people see kids in baggy pants and hoodies, especially walking in a group, they just think they're up to no good," said Ethel Cox, whose children are grown. Cox and other parents, who all said they started having "the talk" with their children from the time they were 5 or 6 years old, agreed that it's different for boys.

"If you're a young black man in this society, that's two strikes against you right there," said Robert Pratt, father of a daughter, 18, and a son, 14. "I tell them if a police officer stops you, you listen, you don't talk back, don't run your mouth. If they arrest you, just keep quiet and call me and let me take care of it. You're not threatening anybody, but if you are perceived to be a threat, anything can happen and then it will be too late."

What about when they're approached by people who aren't authority figures, such as in the Trayvon Martin case? "I'm surprised it hasn't [happened] already," Pratt said.

Latrina Lawson of Crystal, mother of three teens, says there's more for her kids to fear in some neighborhoods than others.

Lawson said that if black teen boys in the congregation walked around in the primarily white neighborhood where the True Apostolic Church is located, she would expect it would put residents on alert.

"Someone would call," she said. "Young folks could be coming from church, but it doesn't matter. It's about how you come off to other people."

Staff writer Bill Ward contributed to this report. Kristin Tillotson • 612-673-7046