BOULDER, Colo. (CBS4)- University of Colorado campus police in Boulder participated in an annual training exercise on Wednesday afternoon in the event that a gunman is shooting on campus.

The training was held from noon to 3 p.m. on Wednesday. It was designed to be as close to what would happen in an active shooter situation as possible.

Officers used simulated weapons that fire pellets. CBS4 reporter Evrod Cassimy and his photographer had to sign injury waivers to be allowed on campus to record the training.

The goal was to determine where the threat was coming from and then stop the threat by either disarming the gunman or getting him to surrender peacefully.

“We had several injured parties in the hallway and they were not sure if they were good guys or bad guys,” Steve Cowles with CU police said.

The officers were instructed to fire upon the gunman if necessary.

“We want to make this training exercise as real as we can for the officers,” Ryan Huff with CU police said. “That includes gunfire, sounds; that includes victims that will be running out.”

“We want to create some tension and some anxiety because nobody wants to get hit,” Cowles said.

Officers trained in several scenarios on campus, including starting outside the McAllister Building and then moving inside to stop a gunman.

Officers eventually coaxed the gunman to put his weapon down and placed him under arrest.

Such exercises have come in handy for officers in their daily police work.

“We’ve had several incidents on campus where officers were told that there’s been an active shooter,” Cowles said. “So these kind of scenarios help us develop a civic response protocol.”

Students and faculty are urged to sign up for campus text alerts if there is a real threat on campus.