The officer fired a gun during an incident near the Field House complex off Westerland Road, where plainclothes officers had been investigating thefts from vehicles.
RNC Chief Robert Johnston said the suspect got into a vehicle at the scene and began to drive away.
"Our officers at one point felt threatened and a shot was fired from a service weapon belonging to one of our members," Johnston told reporters late Tuesday night.
Johnston refused to describe the details of the exchange, including exactly why officers felt threatened enough for one of them to use a weapon.
An officer was slightly injured as the sport utility vehicle raced away from MUN. The vehicle was later found burned on Keane Place, a cul-de-sac off nearby Freshwater Road.
The incident near the Field House started around 7 p.m., with marked police cars racing to the scene. Amid the confusion, students were kept inside the Field House until authorities were sure there was no risk to the public.
Hours after the burned car was found, police blocked off Rotary Drive, west of Columbus Drive.
A male suspect was taken into custody and is expected to appear in provincial court on Wednesday.
Johnston said he asked Tracy Hardy, the RCMP's commanding officer in Newfoundland and Labrador, to handle "the investigation in relation to the actions of the RNC officers."
The incident put students on edge.
"I saw people trying to get into a SUV that was up on the bank of snow, and then another car had blocked it off," said a woman who witnessed the confrontation, and who is not being identified by CBC.
"I pulled ahead a bit more and saw that police had their guns drawn. I didn't hear a gunshot but I did see a hole and the glass was broken in the driver's side of the vehicle."
Ashley Martin told CBC News she and her friend were walking out of the Field House just after it happened.
"There was yellow tape all over the place and there was RNC officers walking around," she said. "The guy that came to talk to us he said they're just waiting for the forensics officer to just like look around or something for casings for their shots were fired."