Chicago police are investigating a reported sexual assault at the University of Chicago’s Alpha Epsilon Pi fraternity house after a 21-year-old woman said she was attacked in a bathroom during a weekend party, according to a police report. The woman told police she had been dancing and drinking at the house at 5625 S. University Ave. before she began feeling unwell as Saturday night turned into Sunday morning. Two friends told police they entered the bathroom and found her not fully conscious, with both her and a man partially undressed, the report says. She was taken to a hospital. The friends said a group of men tried to keep them from entering and had been cheering or encouraging what was happening inside, according to the report. One friend said a man grabbed her by the hair as the other worked to open the bathroom lock. The report says the man in the bathroom responded that everything was “cool” when told to get off the woman. The University of Chicago said Tuesday that a person of interest had been identified. The person has not been named or charged and is not affiliated with the university, according to the university’s alert. The school said it provided police with witness statements and video evidence from university cameras and license-plate readers. No one was in custody as of Tuesday evening. The woman is not a University of Chicago student, according to the police report. A friend told police that the woman was shaken and concerned about her identity becoming public. The friend also said she was frustrated by how long it took to administer a sexual-assault forensic exam. The university’s Alpha Epsilon Pi chapter said it was cooperating with authorities and that no one affiliated with the chapter was involved or complicit. The fraternity’s national organization directed the chapter to pause events and programs while the investigation continues. The case has renewed scrutiny of fraternity-party safety among students. Catie Kirk, a University of Chicago graduate student, said the report raised broader questions about fraternity culture. The investigation remains ongoing.