The girl in the halter top with long hair and pink lipstick stood on a corner at 19th Avenue and International Boulevard and stared at her phone.

Two blocks up, another girl, in white, knee-high boots and a short, leopard-print skirt, was ambling along the sidewalk.

"There's another one," said Barbara McClung, director of Behavioral Health Initiatives for the Oakland school district, as she drove by a church, a boarded-up building and families pushing strollers along the boulevard.

The girls looked young, maybe 16, and were almost certainly selling themselves along the 40 blocks called the Track, an area considered a national hot spot of child trafficking.

Every instinct told McClung to stop the car and rescue the girls. But she knew she couldn't. It would be likely to put them in danger, and they would probably resist anyway.

McClung knew that she and other school district officials couldn't fight the problem on the streets. But they could take it on in the classroom. Their goal, starting in the spring, is to give every seventh-grader in an Oakland public middle school an education on sexual exploitation and how to stop it.

The curriculum was created by Love Never Fails, a nonprofit in Dublin that works to protect and remove youths from child trafficking. All seventh-graders would experience a classroom presentation or assembly focused on healthy relationships as well as exploitation.

Guidance for boys, too

Educating boys would be just as critical as educating girls, McClung said.

"One of the things we hope will come out of the program is deterring boys from becoming pimps," she said. "That's one thing some aspire to be: a pimp."

Students more at risk for exploitation - those with prior abuse or time spent in unstable homes, for example - would be eligible for a six- to eight-week group program with individual mentoring.

That's the plan, anyway. It will cost $40,000 to $50,000 per year to bring the curriculum into all the district's 15 middle schools - money the district doesn't currently have, McClung said.

"It's really cheap," she said. "It's just we don't have any money for it."

Sold for sex

The child-trafficking issue started to percolate within the school district a couple of years ago.

Parents and teachers started asking about it after seeing young girls on the Track. They were students, some as young as 12, being sold for sex when they weren't in school.

District and school officials decided it wasn't just a problem for the police to solve.

"There were so many young girls out there during the day," McClung said. "We knew that we had kids that were involved already."

The issue was already on the radar of community groups and local law enforcement. The FBI designated the Bay Area as a "high-intensity child prostitution" area in 2009 and two years later created a special "innocence squad" in Oakland to address child exploitation, assigning 10 to 15 agents to a team to address underage sex trafficking.

Still, an estimated 100 children are sold for sex in Oakland on any given night, according to the West Coast Children's Clinic and local police. On average, they are 12 to 14 years old when they start.

Since 2004, more than 1,000 sexually exploited minors have been referred to community programs funded by Oakland's Measure Y parcel tax, according to the school district.

"These children are pressed and enslaved in this practice," said Peter Lee, an FBI spokesman. "They're selling their bodies as a minor, as children for sex.

"It's a conversation that everyone needs to have."

Compliments and gifts

The girls on the streets are lured from malls, youth programs or group homes, often by men who ply them with compliments and gifts. Sometimes they are recruited by school friends. Many are foster children; some are homeless; a lot of them have been abused.

"For those girls with low self-esteem, they might be drawn into a pimp saying, 'Hey you're beautiful,' " said Betty Ann Boeving, founder and executive director of the Bay Area Anti-Trafficking Coalition. "There are a lot of populations that are vulnerable."

Warning signs include girls showing up to school with their hair and nails done, wearing fancy clothes, carrying expensive bags and, maybe, sporting new tattoos. They're paid for by someone they often consider a boyfriend, often an older man who sells them on the street. The girl is trapped by a psychological bond formed through duress, seduction and fear, community advocates say.

It's a misnomer to call this prostitution, said Ashlie Bryant, co-founder of the nonprofit Run for Courage, which tries to educate people about human trafficking.

"In our society we think there's a choice," Bryant said. "But in reality, no child wakes up and says, 'Today, I'm going to sell myself.' "

The men - and even boys - can make a lot of money off the girls. Local gangs and other organized crime networks are increasingly seeking the financial windfall associated with trafficking, law enforcement officials said. It's lucrative but carries less of a legal risk than drug dealing.

"We're now seeing these rings who are trafficking victims," said Alameda County District Attorney Nancy O'Malley, who created a task force to combat human trafficking. "I think we're seeing younger men getting involved in exploiting youth - someone who might have gone and become a drug dealer."

Instead, they are using young girls as human ATMs, she said.

Rescuing a girl can take years, requiring physical separation from pimps as well as a kind of mental deprogramming. The girls often end up back on the streets.

"The coerced are the last ones to believe they're coerced," O'Malley said. "She starts at 14, but by the time she hits 19, this is the way she lives."

A holiday on the street

Back on International Boulevard, McClung continued driving south past two more girls at 28th Avenue and three others at 37th. It was early Monday afternoon, a school holiday. Instead of studying algebra functions or the structure of cells, the girls were on the street.

At 45th Avenue, McClung stopped to let pedestrians cross the street, giving her a chance to scan what she said were particularly notorious corners.

"The girls I've seen here are really young," she said. "The pimp is parked right down the street."

McClung hopes a foundation or benefactor will step forward to pick up the tab for the program in Oakland schools.

Years on the streets

Leah Albright-Byrd wishes there had been something like the program for her when she was a child. Instead, she was trafficked on the streets of the Bay Area, Sacramento and Nevada for four years. She was 14 the first time.

She wishes someone had told her that pimps can look like boyfriends, can pretend they love you.

"I actually think it would matter, especially in middle schools," said Albright-Byrd, who founded a nonprofit to support victims of exploitation. "I'm telling you if someone had told me pimps are real, told me I would be vulnerable to predators ..."

She calls the nonprofit Bridget's Dream, after a friend who was trafficked and later killed by a john.

Now 30, Albright-Byrd is helping to draft legislation requiring sexual trauma and exploitation curriculum in the state's middle schools.

"Kids can be highly influential on one another. Imagine the power of kids to be that voice, to come up against that stuff at their schools," she said. "Prevention is where we really have to focus our energy."