A woman was brutally gang raped - after using the popular "meet-up using a social media app" Tagged. Police say the Milwaukee woman was blindfolded and sexually assaulted at gunpoint -- and they fear there are more victims out there.

The app "Tagged," is advertised as a place to chill, chat and go live. The app has 300 million registered users, and is similar to the dating app Tinder. 

Well prosecutors say that the predators used Tagged to commit these heinous crimes.

Davoncia McAfee, 21, faces serious criminal charges in connection with the alleged sexual assault of a 19-year-old woman in the city. He's charged with first degree sexual assault (forcibly aiding & abetting), and Kidnapping (carries forcibly).

The 19-year-old victim told police "she met an individual named 'Kels' on an app called 'Tagged'" and that's where the nightmare began.

The woman got into a vehicle with McAfee, and was kidnapped. A second male "popped up from the back seat and wrapped his arm around her face and neck. This individual then pointed what felt like a small-caliber handgun to the back of her neck and then he said, 'get back here.'"

She was driven to a house, where the unthinkable happened.

The complaint says the woman was then led up a set of stairs into an apartment where the alleged victim said "she heard at least six different voices in the home." The complaint indicates "for approximately five hours" the woman was sexually assaulted by McAfee and several others in the apartment. Eventually "they agreed to take (the woman) back to her car, and her blindfold was on during this time." When the woman was dropped off, the people inside the vehicle "told her not to turn around or they would 'blow her head off.'"