DENVER (CBS4) – A rally held by a “Patriot Muster” group had just ended on Saturday afternoon. Their camouflaged security cleared the area near the Denver Art Museum when the trouble occurred.

(credit: CBS)

Photographer Brian Loma recorded it.

“We all looked up. We saw a spray of pepper spray poof into the air and then a guy, a shot.”

Moments later police rushed in and ordered a man to drop his gun. He was later identified by Denver police as a security guard. Denver TV station KUSA reported Matthew Dolloff, 30, was a contractor for them.

Doloff had his first advisement hearing Sunday morning. The judge declared the arrest affidavit will be sealed, and the defendant will be held on first degree murder charges without bond.

Matthew Doloff (credit: Denver)

Video shows an argument taking place just before the chemical agent is dispersed. It ends with the shot fired.

“The man had his arm up, gun in his hand and shot him point blank range.”

(credit: CBS)

The man who was shot was taken to a hospital where he was pronounced dead. He was identified by rallygoers as a man who had attended the Patriot Muster rally.

Until the shooting, the rally was peaceful. Protestors identifying themselves as anti-Facist, communists, and pro-Black Lives Matter were kept at a distance.

(credit: CBS)

Denver police kept a strong presence during the event.

“Our primary purpose is to deescalate the situation. We can’t have any further violence in conjunction with what happened today,” said Division Chief Joe Montoya.

It does not appear the violence had a direct link with one side opening fire on the other.

KUSA says one of its producers was taken into custody and was released after it was determined he had nothing to do with the shooting.

The security guard is still being held.

Rick Sallinger