The suspected shooter, 31- year-old Tyriq Williams of Northwest, was arrested by D.C. police officers on Friday.
Investigators believe Williams is responsible for shooting and killing 20-year-old Terry Clark of Southeast.
Officers responded to the shooting Saturday just before 8:00 p.m. in the 1200 block of Half Street, not far from Nationals Park.
Once there, officers discovered a man who had been shot outside an entrance for the Navy Yard Metro Station
Officers performed CPR on Clark, but he was ultimately pronounced dead at the scene.
Metropolitan Police Department officials confirm the shooting is being investigated as a homicide.
Williams has been charged with first-degree murder while armed.
The investigation is ongoing.
Anyone with information is asked to call MPD at 202-727-9099 or send a text tip to 50411.
This is a developing story. Stay with FOX 5 for updates.