Rhode Island State Police say it may have been a woman's shrill scream in the URI lecture hall on Thursday that caused widespread panic and pandemonium around campus.
Capt. Frank Castellone of the Rhode Island State Police told NBC10, "Somebody heard something that happened outside the classroom, they reacted to that and as a result of that reaction, it went viral. Peoples' reaction to that was obviously severe and there was panic in the classroom."
Since the incident, state police have been working around-the-clock to identify and interview witnesses.
Detectives are reviewing the same audio tape NBC 10 obtained on Thursday from a URI student who was recording the professor's lecture in the crowded building at the time.
Capt. Castellone said, "We've have several accounts (as to what was heard). Some people have told us that they heard, 'I'm a nice guy,' some have said they heard 'I'm a good guy."
Castellone says that recording has actually been a big help.
"It is. Any time we have any audio or visual it's part of our investigative techniques," he said.
But state police say so far, not one of the 200 plus witnesses they've interviewed has said, for sure, that they heard the word 'gun' from the original man who yelled.
"Everyone we interviewed has told us pointedly that they did not hear the word 'gun' first hand," Castellone said.
Most URI students NBC 10 spoke with agreed with that state police assessment.
Mihir Subash is a URI Freshman.
"I think it was an overreaction. I think the girl, (who screamed) she just said the first thing that came to her mind, because the guy, (who yelled the phrase) he didn't really say anything that sounded too crazy, and the girl made an assumption, which made everybody run for their lives," Mihir Subash, a URI freshman told NBC 10.
URI Freshman Ingrid Felso says she's not quite sure what to believe. "Some people are like, 'Oh my roommates friend was in that class, and they heard someone, the person, supposedly shouting, 'I'm a good guy,' or something like that, which they mistook for the 'gun' word, was inside the class, and the someone else said he was outside the classroom, so I have no idea what happened."
But not every student is convinced the answer is that simple.
"I think he had a gun, and I think he got away with it. I think they're giving up too easily really," said freshman Kelsey Law.
State police told NBC10 the investigation into this incident is far from over.
In fact, the department says it's still too soon to say whether that on campus URI group, "Humans vs. Zombies had anything to do with the incident at all.
Capt. Casetllone, Col. Steve O'Donnell, and every detective in their department are very interested in talking to the two key people who can be heard on that audio recording.
Castellone said, "We have not yet been able to positively identify the male voice heard yelling the phrase, or the female voice screaming in reaction to it."
If you have any information about this case, no matter how insignificant it may seem, you are urged to call the state police at (401) 444-1000.