The shooting took place at about 9:50 p.m. on Wednesday (01:50 GMT on Thursday) on Massachusetts Avenue NE, east of North Capitol Street, The Washington Post said.
All doors to US Capitol secured by USCP & remained closed after shooting near Union Station & Postal Museum just on edge of Capitol Hill. Victim is in critical condition. Police looking for 3 suspects.— Chad Pergram (@ChadPergram) November 1, 2018
The man was found unconscious and sent to a hospital, the newspaper added.
Homicide detectives have launched an investigation into the incident, however, no further details have been provided so far.