The Denver District Attorney’s Office said on Thursday it will drop second-degree murder charges against Matthew Dolloff over the fatal shooting of Lee Keltner in 2020.

Denver District Attorney’s Office spokesperson Carolyn Tyler said in a statement that after fully considering the facts and circumstances surrounding the charges, the office had informed Keltner’s family members on Thursday that it would soon dismiss the criminal case against Dolloff. Tyler did not specify a date.

“In line with our ethical obligations, we cannot overcome the legal justifications of self-defense or defense of others,” Tyler said in a statement. “We are not able to prove guilt beyond a reasonable doubt.”

Dolloff was charged in October 2020 after police said he fatally shot Keltner after dueling rallies between “anti-fascists” and “patriots” downtown on Oct. 10, 2020. The shooting, which unfolded after Keltner hit Dolloff on a Saturday afternoon, was captured in videos and photos. It happened close to Civic Center Park, near Denver Public Library’s downtown branch.

Dolloff faced between 16 to 48 years in jail if convicted. He was working as a security guard for 9News when the incident occurred. The news station said in 2020 it did not know Dolloff was armed when he was hired, and authorities said he was not licensed as a security guard in the city at the time of the shooting.