The Pharr Police Department says it's documented 15 to 20 cases of human trafficking in a two-year span. Those cases had links to other cities outside Pharr, said Pharr PD Human Trafficking Liaison Nancy Gonzalez. She said those cases did not result in local charges.

"For the last 7 years I worked for crime victims and I noticed there was a rise in human trafficking,” she said.

The Pharr Police Department hopes to raise awareness about signs and red flags. They held a workshop Saturday morning so educators, first responders and others could understand the issue. 

Human trafficking differs from human smuggling in that people are being transported against their will or to work for others, Gonzalez said.

Gonzalez's is a rare position in local police departments. She said some local federal agencies have liaisons like her, but to her knowledge, she is the only human trafficking liaison working for a local police department in the Valley.

The signs of human trafficking are subtle.

"The trafficker tends to speak for the victim. So when we interview the victim, they don't know what to say,” Gonzalez said.

A case may have started in the valley, but has links to Houston or other large cities. Interim chief Juan Gonzalez often said they're traveling through the Valley.

"They'll enter through here, but then wherever their destination is, I think that's where that might be happening,” Juan Gonzalez said.

"They're not going to speak to you right off the bat,"Gonzalez said. "They're going to look away, they might have a hard time speaking clearly, but their body language is going to tell you a lot, whether that person has been forced for a while to do things that they don't want."