The 18-year-old, named Janya Williams, is now facing a felony offense.

Williams allegedly sent her Andy Frains supervisor an anonymous text message, via TextNow, which detailed the threat.

When the supervisor contacted higher authorities, who then alerted the FBI, Williams shared a screenshot of a Facebook post detailing the threat.

Williams alleged that her sister also saw the post.

The Facebook post declared that a “massive shooting” would occur at the Lollapalooza location, with “150 targets.” 

Detectives now believe that Williams created the post under a false Facebook profile named “Ben Scott.”

According to the New York Post, an FBI analyst traced the origin of the post back to Williams’ IP address and iCloud.

Williams allegedly admitted to creating the fake threat because she “wanted to leave work early.”

According to ABC7 Chicago, she has appeared in bond court and is being held in custody pending $50,000 bail.

Williams is due back in court on Monday.