Matthew Dolloff, the armed security guard working for 9News at a conservative rally in Denver Saturday, will be charged with 2nd degree murder of conservative demonstrator Lee Keltner.

Widely distributed video from the incident shows Keltner was involved in a heated verbal argument with a left-wing counter-protestor identified as Jeremiah Elliott before he turned his attention toward news photographers and Dolloff.

Keltner sounded angry that he was being photographed by 9News and appears to slap Dolloff, then steps back. Dolloff fired his gun as Keltner sprayed OC — pepper spray.

Footage of Elliott after the incident shows him walking away from the scene and taunting the conservatives with obscenities.

Dolloff faces a mandatory sentence between 16 and 48 years in prison if convicted.

According to the Denver Post, Colorado law says deadly force can be used in self-defense if one reasonably believes using “lesser force won’t be sufficient to stop an immediate threat against themselves or others.”

9News appears to be distancing themselves from Dolloff, claiming they are not responsible for the fact he was unlicensed to carry the weapon as a security guard, and say they did not know he was armed.

A Denver City Attorney spokesperson previously indicated 9News could face both civil and criminal action for deploying an unlicensed security guard.

Early reports suggested Dolloff could be a sympathizer with left-wing activists, with a connected YouTube account showing footage of “Occupy Wall Street protests and a Bernie Sanders rally in 2016.”

9News host Kyle Clark has since deleted a series of tweets where he mocked the idea Denver has become increasingly dangerous, even as his network was hiring armed security for its reporters.

According to Red State, Clark is described in a tweet by a BLM/Antifa account as “‘one of us’, and that he would not need security at a BLM/Antifa protest because they would protect him.”

9News reporters and producers have been taken off the story. The station brought in a reporter from WFAA ABC Dallas to cover the investigation.