Officers were able to collect an orange bucket left behind at the scene. It has been sent for forensic testing so that police can pinpoint exactly what is inside.
It's "really demeaning for someone to do that because no one just does that, I think, spontaneously", Sabrina Olaso, a first-year student at the university told CBC News.
Another student, Jacob Masih, said he may reconsider spending time at the campus after the incident.
"I'm kind of scared so I might go home. For me, I'm a commuter and I walk a lot so I'm not trying to get that stuff put on me," he said.
The previous incidents occurred at the University of Toronto's Robarts Library and York University's Scott Library — which are in close proximity.
An unsuspecting woman sitting at a table in Scott Library was the suspect's previous victim.
"At approximately 5:00 p.m. yesterday [Sunday], an unknown male entered Scott library and deposited a substance, suspected of containing faecal matter, on a student," a spokesperson for York University told CTV News Toronto on Monday.
"York University Security Services responded to the incident. We have reached out to the victim of the assault to offer support. We are also investigating the incident and working with Toronto Police Service."
The man then fled the area afterwards, police said. Investigators confirmed the bucket contained liquefied faecal matter.
A security camera image of a suspect wanted in the connection with the incident has been released by investigators.
A student at University of Toronto told CP24 she was in the library at the time of the incident and will "never forget the smell".
"I thought it was coffee or something," Kaylie said.
"All of a sudden the smell hit.
"I thought I was going to faint. Me and my friends packed up our stuff and ran out of the room."
Authorities said the two police divisions investigating the case will likely work together due to the similar nature of the incidents.
