NEW VIDEO: What led to a justified, deadly shooting at Stargate nightclub

Ramsey County prosecutors said a deadly shooting at Stargate nightclub in Maplewood, Minn. on May 28 was justified when an armed security guard shot and killed one of six people who apparently attacked him.

This means there will be no criminal charges against the un-named security guard who pulled the trigger outside the club killing 20-year-old Chou Yang.  Yang’s loved ones have wanted the armed security guard charged with murder -- but prosecutors say what happened that night was a justified use of deadly force.

The surveillance video from a neighboring business showed authorities just about all they needed to see to justify the deadly use of force. The security guard was chased out into the middle of the parking lot by a group of seemingly angry patrons.

He was taken to the ground, punched and kicked. The security guard told authorities he blacked out and feared for his life.

Maplewood Police Chief Paul Schnell walked Fox 9 through the video's critical moments.

"It's at that time he believes quickly he is in danger,” Schnell pointed out in the video.  “His life is in danger. He indicates, he tells them to stop. They don't. And he fires. That happens within seconds."

In the end, Yang was struck twice and died at a Saint Paul hospital.  Police concluded that he was in the process of getting kicked out of the nightclub for underage drinking. Security had his I.D. and was writing him a trespassing notice when the confrontation escalated and poured out into the parking lot.

Schnell called the whole thing a senseless tragedy.

"Just getting kicked out of the bar, that's the crazy part,” Schnell said. “What really started out as a simple, here is your trespass notice, don't come back and that would've been it, ends up with a young man losing his life.

Yang's wife was with him at the club that night, and asked for criminal charges against the still un-named security guard.

Police redacted his name from the public file. Schnell explained that his life has been threatened numerous times since the deadly altercation nearly six weeks ago. And out of concerns for his safety, the sergeant's name was blacked out.

The 28-year old security guard still works for the private security contractor, JBM patrol and protection, which was hired by the nightclub for their 18-plus "sexy mayhem" night on May 28. But JBM no longer works with Stargate -- the two parties severed their relationship in the volatile aftermath of that shooting.