UPDATE: Denver’s District Attorney Office on Tuesday, Nov. 27, said they had formally charged Joshua Hayward with 28 criminal counts, including one count of first-degree murder-after deliberation, for his alleged involvement in the shooting. He is charged separately from Dashae Eugene Armstrong, who police said was also involved in the shooting but was charged by federal authorities. The DA’s office identified the victim who was fatally shot as 59-year-old Terrance Wardlow, who was a bystander.

A man authorities believe was involved in an exchange of gunfire in downtown Denver that left one person dead appeared in U.S. District Court Wednesday on pending firearm charges.

Dashae Eugene Armstrong, 23, appeared in U.S. District Court Wednesday morning to be advised of pending firearm charges for his alleged involvement in Monday’s shooting in LoDo, according to a release from the U.S. Justice Department. Monday’s shooting left one man dead and four other people (including Armstrong) injured.

Federal authorities believe the shooting involved rival Crip gang members.

Armstrong was taken into custody after being treated at a hospital Monday. He was found with a gunshot wound to his leg after police responded to the shooting at 1200 21st Street at about 4 p.m.

Denver police found five shooting victims, including one man who was pronounced dead at the scene. The man’s name has not been released.

Authorities believe Armstrong, a Tre Deuce Crip gang member and a convicted felon, exchanged gunfire with a member of the Tre Tre Crip gang. The second person is not identified in the DOJ’s release. The release said witnesses saw two men exchange gunfire, one of whom was described as a heavy-set black male wearing a grey sweatshirt and black pants.

Denver Fire Department first responders later found a male in front of the Marquis Theater matching the description. He was later identified as Armstrong.

Detectives at the scene found two groups of spent shell casings, including one group of 9mm casings matching the gun Armstrong allegedly used.

On Tuesday, Denver police said they arrested Armstrong and Joshua Hayward, 23, in connection with Monday’s shooting. Hayward is being held on investigation of first-degree murder. Police said he fled the scene in a car before being arrested Tuesday morning.

Armstrong’s criminal record dates back to 2007. According to the DOJ’s release, Armstrong was convicted of felony distribution of a Schedule I/II controlled substance in Denver District Court in November 2013 and the same felony charge in Denver District Court in May 2014.

U.S. Attorney for Colorado Jason R. Dunn said the office filed charges as “part of the law enforcement and prosecutorial response to this violent crime.” The release said the investigation into the shooting was conducted jointly by Denver police with help from the ATF’s office in Denver and the Safe Streets Task Force led by the Denver Division of the FBI.

“We work together with our state and local partners and will step in when state prosecution is not feasible or possible,” Dunn said in the release.

Armstrong is facing one count of being a felon in possession of ammunition. He could face up to 10 years in federal prison and an up to $250,000 fine if convicted. His case is being prosecuted by Assistant U.S. Attorney Celeste Rangel.