Commercial sex trafficking is a problem worldwide and here in the Valley.

But, the issue has only become a law enforcement priority in recent decades, and it’s just beginning to emerge as an area of responsibility for local police departments. It wasn't until 2013 that the FBI incorporated human trafficking as an offense in the uniform crime reporting system.

A recent study by Arizona State University’s Center for Violence Prevention and Community Solutions looked at how pervasive the problem is and how local police agencies are dealing with it.

“Most research in human trafficking in this country relies on federal statistics and federal activity,” said Vincent Webb, professor of practice with Arizona State University’s School of Criminology and Criminal Justice with the Center for Violence Prevention and Community Safety. “There’s very little research that has looked at human trafficking from the perspective of local police agencies.”

At the same time, statistics about trafficking worldwide are inconsistent in estimating the true magnitude of the problem.

The study surveyed 72 of the nation’s largest police departments and found prostitution is moving from the streets to online.

Of those departments, 80 percent reported that online sex advertising is up, but, street prostitution is down, Webb said, while 40 percent of respondents indicated a decrease in street prostitution.

Sargent Kathie Click with the Tempe Police Department’s special victims unit said law enforcement’s perception of the problem has changed in recent decades.

“We always thought of it like prostitution,” she said, “a victimless crime.”

But, more recently, the education and the training that law enforcement officers are getting is that the average age of entry into this lifestyle is 13 to 14 years old.

"That’s not a victimless crime at all,” Click said.

Teenage girls can be particularly susceptible to being reeled in by traffickers, Click said.

They’ll often contact them on social media – Facebook, Twitter, Instagram, Snapchat, she said. “And then they start meeting those basic needs that aren’t being met in other areas, whether that’s shelter, food, clothing or if it’s just that emotional needs aren’t being filled,” Click said.

In one case, she said one of the girls who had been trafficked said, “I don’t know what they’re complaining about. They were giving us cheeseburgers.”

“She wasn’t getting food at home, so that was the need that was being met for her,” Click said.

When it comes to combating trafficking, she said it’s essential that they stay up on current technology in order to stay in the mix and be able to track crimes through social media.

The ASU study also found that departments reported a lack of resources to address sex trafficking, a problem Click said is difficult for smaller departments like hers to tackle.

Tempe police doesn’t have a vice unit that’s focused on fighting trafficking. “If resources were unlimited, of course I would love five, 10 more people to just have somebody to focus on that,” Click said.

But, as it stands, inter-departmental coordination is essential.

She said it’s just one street that separates Phoenix, Tempe and Mesa. “So it doesn’t really matter to me what side of 48th Street a victim is on, I want to be able to provide them with whatever they need."

Webb said he is working on developing a vulnerability index that will show how likely a community is to have a trafficking problem.