MOBILE, Alabama -- Surveillance camera footage from the University of South Alabama shows in detail the two-minutes-long confrontation that led to the shooting death of Gil Collar at the hands of a USA police officer.

The video shows Collar, 18, approaching the locked door of the USA police station at 1:23 a.m. When he's unable to open it, he leaves for one minute before coming back and banging on one of the windows on the building, apparently using all his strength.

He hits the window six times, throwing his arm back behind him and changing his posture in an apparent attempt to use the strength in his legs.

Completely naked, Collar then walks away from the police station and out of frame.

At 1:24 a.m., footage shows USA police officer Trevis Austin, 27, come out of the station with his gun drawn.

According to deputies, Austin had been working on a report at his desk when Collar hit the station's windows. He had set his lapel camera to charge mode and not recording, officials said.

By the time Austin came out of the building, the video shows Collar had moved to the grassy area in front of the police station. When Austin appears, Collar immediately moves toward him.

Austin starts backing away, moving parallel to the building and Stadium Boulevard.

For a few seconds, Collar advances on Austin, moving into various fighting poses. When the pair hit the grass on the other side of the police station, Austin moves toward Stadium Boulevard in an attempt to move back down the building.

It's around here where details in the video become hazy.

Only 30 seconds after Austin responds to Collar hitting the station windows, he fires the fatal shot at the freshman. Austin is no longer in frame when the shooting occurs, but Collar clearly falls onto the grass.

A USA police dispatcher, who was inside the building during the confrontation, runs in front of the building as the shot rings out.

At around the same time, backup arrives in the form of another officer. At this point, the trio is on the grass in front of the station. Collar gets up immediately after being shot and moves toward the officers again, taking him out of frame.

"It's pretty obvious [that the shot didn't stop him]," said Mobile County Sheriff Sam Cochran.

The officers regroup and move back into frame with their backs toward the station. Collar runs between them before collapsing on the ground again.

A third officer arrives on scene moments later.

The whole video, from when Collar initially tries to get into the police department to when he's shot, lasts only one minute and 52 seconds. When the time it took for the third officer to arrive and the scene to settle are factored in, the video lasts two minutes and 49 seconds.

Cochran said the video is evidence of just how fast the situation escalated.

Since Austin came out of the police station with his gun drawn -- as Cochran said he believes any officer would -- the length of the confrontation puts into question whether Austin had the time to holster his gun and grab a non-lethal weapon.

"Don't jump to the conclusion that this officer had an opportunity to use all his equipment," Cochran said.

According to Keith Ayers, public relations officer for USA, all campus police officers are issued pepper spray and batons. However, officers do not have Tasers.

Reporters were shown the surveillance video by the Mobile County Sheriff's Office today. No one was allowed to take pictures or record the video.

Cochran said the department will not be releasing the video publicly for fear of tainting the evidence.

Earlier today, the Beasley Allen Law Firm said on behalf of Collar's family that they saw nothing in the video to justify the use of lethal force.

Students and community members protested outside the USA police station Wednesday to demand officers get more training and Tasers.

Collar, of Wetumpka, was shot and killed on Oct. 6

, according to deputies. Deputies said he assaulted people in two cars before heading toward the police station.