Two buildings were evacuated on Friday afternoon in the area of Harrison and Racine, near the University Pavilion.
The only shot fired on campus on Friday was by a university police officer who accidentally pulled the trigger while responding to this security scare.
It's one that some students complain they weren't told about quickly enough.
The UIC campus was quiet on Friday night, save for a few officers who remained at the Student Services Building where hours earlier there were reports of gunfire.
"I actually didn't hear any gunshots but I wasn't going to stick around to hear it either," said Jasmine Donnelly, UIC graduate student.
Jasmine Donnelly was among the hundreds of students and staff who immediately evacuated the Student Services Building as heavily armed officers searched for a gunman. After finding no shell casings, no eyewitnesses, and nothing suspicious on campus security cameras, police now conclude there was never a shooter.
"We have no information that it's a prank. I have no reason to doubt there was a noise that people thought was gunfire," said Mark Rosati, UIC spokesperson.
"I actually personally found out from my cousin in Woodstock who told me about it. She sent me a text. She heard before I had, and I was right on campus," said Bryan Tobin, UIC student.
Bryan Tobin is among those critical of campus security for not activating a text and email alert system.
Some students found out about the shooting when friends and family copied and sent an advisory placed on the school's Web site.
UIC's system was put in place after the shootings at Virginia Tech in 2007.
"They don't have to start a scare, just a simple message that says 'there's a possible situation at SSB, be aware.' That's all it took and they didn't do anything," said Tobin.
"I think it's important to have sirens, audio saying what's happening. I really just had friends text me and say, hey, I heard this happened," said Roshina Khan, UIC student.
A school spokesperson says that within ten minutes police were fairly certain that there was no gunman, no life threatening situation and therefore no need to send alerts to students and staff.
There are, however, plans to install loudspeakers on campus to warn of everything from shootings to tornados.