The incident occurred at about 4 a.m. at East Capitol Street and Second Street, Sputnik news agency said.
According to DC’s Metropolitan Police Department, when officers heard the gunfire, they started approaching the man when he shot himself. Nobody else was hurt as a result of the incident.
Police added that they are handling the investigation of the man’s death and are also looking into his background.
“At this time, it does not appear the man was targeting any Members of Congress, who are on recess, and it does not appear officers fired their weapons,” a statement by the police says.
Sunday’s incident outside the US Capitol came at a time when police officers and FBI agents across the country have been receiving threats following the FBI’s search of former President Donald Trump’s Mar-a-Lago estate in Florida earlier this week.