Video shows seconds before and after fatal shooting at Denver protest

Verbal altercation quickly escalates leaving one dead and one in custody

Newly released cellphone videos show the seconds before and after the deadly shooting that occurred at a protest in Denver.

Matthew Dolloff, a private security guard hired by a local TV station, shot and killed a man who maced him, now identified as Lee Keltner.

Mr Dolloff is currently detained on suspicion of first-degree murder in connection with the shooting, Denver police have said.

In the first cellphone video, a verbal confrontation begins between two men in the outside space between the Denver Public Library and Denver Art Museum.

As the altercation gets heated, a third man attempts to physically separate the pair.

One of the men, wearing a black t-shirt, says: “Don’t touch me, I’m standing my ground.”

The second man, believed to be Mr Keltner, wearing a hat, sunglasses, and a mask, is holding a can of pepper spray.

Mr Dolloff and Mr Keltner became involved in an altercation while the latter was arguing with another person, according to Denver police records.

At 3.36pm Mr Keltner, reportedly angry at being filmed by a producer for the station, struck Mr Dolloff on the side of the head with an open hand.

Just before the footage ends, a man’s voice can be heard to say: “Get the cameras out of here or I'm going to f*** you up."

The pair are shown briefly scuffling before the video stops.

Mr Dolloff then draws a handgun from his waistband and shoots Mr Keltner who is discharging his pepper spray. 

Mr Dolloff was taken into custody by uniformed officers while holding a semiautomatic handgun.

In the second cellphone video, a man can be heard yelling that he works for 9News, another says that he has a press pass.

“The guy on the ground was going to mace me,” a man can be heard saying. “That was my security guard, he just protected my f***ing life.”

Mr Dolloff was hired by the TV station from the security company Pinkerton, an arrangement that had been in place for months. 

Records show that Mr Dolloff does not have a licence to work as a security guard in Denver and authorities are looking into how he was allowed to work.

Images of the shooting scene from The Denver Post show that Mr Dolloff placed his body between the protesters and the reporter that he was working to protect, his lawyer, Doug Richards, said on Monday.

“He was doing what he was supposed to be doing there,” Mr Richards said, adding that the shooting was self-defence. The Denver Post first reported his comments.

The shooting occurred during a “Patriot Muster” that was met by a counter-protest by groups calling their own rally a “BLM-Antifa Soup Drive”.

Police kept the groups separate and there were no other arrests.

With reporting from the Associated Press.