They say 29-year-old Steven Martin Robinson should be considered armed and dangerous.
Police began investigating after they responded to the residence in the 800 block around 4 a.m. on July 12 and found 28-year-old Shanika Williams suffering from a gunshot wound.
Emergency personnel at the scene confirmed that Williams had died.
Police are looking for Robinson on a charge of second-degree murder while armed.
If you can help police find him, call (202) 727-9099.