Deahvion Austin was initially reported missing by her mother on Monday, a spokesperson for the Chicago Police Department told BuzzFeed News Tuesday.
Detectives are now conducting interviews but no one has been charged in the alleged attack. She told Johnson her daughter had been missing since Sunday and showed him images taken from the video of the alleged assault.
The girl's mother, Stacey Elkins, said the video showed her daughter in various stages of undress with several young men.
"For you to do something like that and then to post it up on Facebook like it's a joke, it's just awful".
The 5-foot-7, 146-pound black girl wears her hair in an Afro, police said. "I just want her back home".
Syria's war : Forced evacuations begin in Al Waer
The fighters and their families are being taken to the northern rebel-held town of Jarablus on the border with Turkey. Al-Waer is the last neighborhood in the city of Homs where armed groups still spread, imposing a siege on the locals.
Police only learned of the latest alleged attack when the girl's mother approached the head of the police department, Superintendent Eddie Johnson, late Monday afternoon as he was leaving a department station in the Lawndale neighborhood on the city's West Side, department spokesman Anthony Guglielmi said.
Johnson escorted her inside to make sure it was handled immediately.
"She was found today [Tuesday] at 7:45 a.m.", the spokesperson said, adding that she was now being treated at a nearby hospital. "I don't know if they have or if she's out there scared somewhere".
Jeffrey Urdangen, a professor at Northwestern University's law school and the director of the school's Center for Criminal Defense, said it isn't illegal to watch such a video or to not report it to the police.
"That's not right", he said.