The killing occurred around 10:50 a.m. Friday in the 3000 block of 30th St. near Naylor Road SE.
Police said officers responded after hearing gunshots. When they arrived, they found a man — who was later identified as Cunningham — and a woman suffering from gunshot wounds, according to a statement.
The woman was taken to a hospital, where she was treated for injuries that were not life-threatening, according to police. Cunningham died at the scene.
Police said an initial investigation found that Hill, the suspect, was also shot in the incident and went to a nearby fire station for help. He was taken to a hospital and was said to be in stable condition, according to police officials.
A day after the shooting on 30th Street, another man was shot and killed a few blocks away, in the 2800 block of Shipley Terrace SE. He was identified as DeAngelo Ross, 22, of Southeast.
D.C. Police Chief Peter Newsham said that “because of the close proximity” of the two shootings, “we are looking at the possibility they are related.”