This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

CHICAGO — The Cook County Sheriff’s Special Victims Unit investigates crimes of a sexual nature, including those involving children.

WGN Investigates was granted exclusive, behind-the-scenes access to the team and its investigators, many of whom work undercover.

The purpose was to provide a glimpse at the dangers that social media and dating apps present, if misused by teens or without proper supervision.

“As a parent, you really have to know what’s going on in your house,” Dion Trotter, a commander of the sheriff’s SVU, said. “These bad guys know how to get in those sites — know how to befriend [the children] and that’s how it starts.”

The unit’s leaders say building the cases can be tough and tedious, and often involve viewing explicit images of children, extracted from cell phones and web sites.

It takes a toll on investigators, but they say it’s worthwhile because of what is at stake.

“We’re putting ourselves between children and the bad guys,” Sgt. Jim Draz, of the SVU, said.

He adds, it’s not the arrest of a predator that’s the biggest reward. It’s a hope that a child or teenager they may never know was saved from abuse or exploitation.

“It’s probably the most rewarding spot I’ve been in,” Draz said. “Because these people, these offenders that are doing these crimes are true offenders. They’re truly evil in certain aspects.”