Philadelphia Police are continuing to investigate whether Friday's alleged sexual assault was committed by a Penn student.
Captain John Darby, commanding officer of the Philadelphia Police Special Victims Unit, said the victim may have seen her attacker on campus before.
"What we have right now is that, at least at first glance, the complainant may have seen this individual at other events or at other times around campus," Darby said.
The reported incident occurred near 40th and Pine streets, in the alley behind Allegro Pizza, around 2:45 a.m. Friday morning.
The assailant is described as a white, college-age male with wavy brown hair.
Philadelphia Police are working with the University to obtain security tapes and conduct interviews with students, particularly those who are acquaintances of the victim, Darby said.
However, investigators have not made any arrests or identified a suspect.
The victim was treated and released from the Thomas Jefferson University Hospital Friday morning. Despite the Hospital of the University of Pennsylvania's proximity to the scene, HUP administrator Kathleen Beer said Jefferson is the primary treatment center for all sexual assault cases in the city.
Darby said the investigation will proceed at a pace that is comfortable for the victim.
"The complainant on Friday was physically exhausted," Darby said. "It is not uncommon for us to let the victim go home and rest."
Police said they do not want students to lapse into a state of fear or alarm. Additional security has been dispatched to the 40th Street area in response to the reported crime, and officials continue to encourage students to exercise common sense while outside.
Ellie Di Lapi, director of the Penn Women's Center, said that 80 to 90 percent of women who report sexual assault say they know their attacker.
