This story was originally published at 4:56 p.m. EDT May 3, 2016.

The Army’s Fort Carson in has largest command in Colorado has decided not to put a controversial biker group known as the "Iron Order Motorcycle Club" on an off-limits blacklist. At least not yet.

"Don't take this as a final decision," said Lt. Col. Jason Brown, a spokesman for Maj. Gen. Ryan F. Gonsalves, commander of 4th Infantry Division and Fort Carson. "Discussion regarding the safety of our soldiers and communities is a continuous process."

The Iron Order is particularly popular among current and former members of the military members and law enforcement, and is already barred at several other military installations.

The Fort Carson off-limits list, part of a May 2015 memo to troops signed by Gonsalves, states that soldiers will not actively advocate, associate with or participate in violent, extremist, or criminal groups, to include outlaw motorcycle gangs.

Officials at Fort Carson had been considering adding the Iron Order to the list in the wake of a Jan. 30 brawl that left a one biker dead in nearby Denver.

Brown said the Iron Order could still be added to the list based on regular meetings between local military leaders and law enforcement officials.

Meanwhile, Denver police say they've completed a lengthy investigation confirming that Derrick Duran, a corrections officer and member of the Iron Order, shot and killed Victor Mendoza, a member of the Mongols Motorcycle Club after a fight broke out between the two groups at biker swap meet.

Duran fired the first shot, injuring one person, said Denver Police Cmdr. Ron Saunier at a news conference. Mendoza returned fire, grazing Duran and hitting another man behind Duran. Duran then fatally shot Mendoza, Saunier said.

About half of the Iron Order bikers involved in the brawl were military veterans from the Colorado area, according to a top leader in the club.

Denver police recommended charging Duran with first-degree murder, said Saunier, but the district attorney's office declined to prosecute the case.

"They do not believe they are able to proceed forward," he said. In a statement, the district attorney's office said "there is no likelihood of a conviction due to the self-defense claim of Mr. Duran."

The decision has shocked some observers.

"It's disturbing, at best," says Dr. William Dulaney, a professor at the Air Command and Staff College at Maxwell Air Force Base, Alabama, and an expert on biker culture.

Dulaney, a former Air Force special operator, says his own sources close to the investigation believe there is little evidence to support Duran's claims of self-defense:

"I am gravely concerned that the Denver District Attorney's office has opened the door for more wrongful deaths in the Motorcycle Club community. And the Iron Order is unequivocally not a part of that community."