▶ Watch Video: 1 dead in shooting at Denver protest A suspect in the fatal shooting during dueling rallies in Colorado will be charged with second-degree murder on Monday, the Denver district attorney’s office said. Matthew Dolloff, 30, could now face between 16 and 48 years in prison for the death of 49-year-old Lee Keltner. The shooting on Saturday occurred near Denver’s Civic Center Park, where both left- and right-wing groups were holding rallies. According to Dolloff’s arrest affidavit, he and Keltner “engaged in a confrontation” as Keltner was leaving an organized rally and Keltner struck Dolloff in the side of the head with an open hand. Citing footage captured on city cameras as well as cell phone video and digital photography, the affidavit said Dolloff then drew his handgun, aimed it at Keltner, and fired one shot as Keltner discharged a can of pepper spray. Keltner was transported to a hospital where he was later pronounced dead. Police said both the victim and the suspect are White males. NBC affiliate KUSA-TV said the suspect was a private security guard hired by the station, but CBS Denver reported days later that Dolloff is not a licensed security guard. “There is no record for an active licensed security guard now or ever for an individual named Matthew Doloff or Dolloff. If he was operating as a security guard, he was in violation of the law,” the Denver Department of Excise and Licenses told CBS Denver. “Security guards are prohibited from carrying or using a firearm without getting an armed firearm endorsement for their license,” the department added. “All security guards in Denver are required to get a federal background check before they receive their license.” Jordan Freiman contributed reporting.