All City of Austin employees are expected to undergo human trafficking training in an effort to raise awareness about what police are calling a prevalent issue in the city.

Sgt. Kevin Covington with Austin Police Department's Human Trafficking Unit said the training is needed because signs of the crime are subtle.

"Most of them have probably seen a human trafficking incident and just didn't realize it," said Covington.

Covington's two detectives came up with the program.

"A couple of females with a male and they're refusing to talk, they won't make eye contact with you... It's like they're not even there, they don't even want to be seen," said Covington, providing an example of a possible human trafficking incident.

With the training, police and advocates hope city workers like trash collectors and code inspectors will pick up on illegal activity that's happening out in the open.

"Be more on the lookout. How any people are coming in, how many people are coming out, why is there so much traffic? Why are there so many women living in one place? Or males as well," said Rachel Alvarez, supervisor of the Survivors of Trafficking Empowerment Program (STEP).

STEP is just one of several services offered by the Refugee Services of Texas, a nonprofit that works directly with authorities. Just last month, Alvarez said she has seen a spike in human trafficking cases in Austin.

"With trafficking, especially sex trafficking moving from clubs and cantinas and into apartment complexes and working as brothel fronts," said Alvarez.

Alvarez said since 2003 when Refugee Services of Texas started working with authorities, they have helped more than 400 survivors.

Human traffic is considered modern-day slavery. The FBI believes human trafficking to be the third-largest criminal activity in the world. It includes forced labor, domestic servitude and commercial sex trafficking, and it involves both U.S. citizens and foreigners alike.

Austin police once thought big events like South by Southwest and Formula One brought more human trafficking to town. But since looking at more data, police said that's not the case.

While they don't know what's causing the recent spike, the unit is working on approximately 40 cases right now. Police said they do know human trafficking will continue to increase in Austin.

"It's such a hub for people with money coming here to party and that's only going to continue. As long as we have 6th Street, it ain't going away," said Covington.

A city spokesperson said the plan is to make the new online program mandatory for employees. It could likely roll out next week.