Police were responding to a domestic incident when the officer shot the man.
According to DC Police Chief Robert Contee, officers responded to the home around 4:30 p.m. to serve a protective order.
Contee says at some point during the interaction, "there was some type of incident and the person was ultimately shot."
Dozens of officers and detectives were on scene investigating Monday afternoon. Family members of the person who was shot and killed were also on scene.
FOX 5 spoke to one family member off camera who said she wanted more answers about what happened.
Police have not indicated what prompted the officer to fire, nor have they identified the man who was shot.
FOX 5 has learned there was a body-worn camera that recorded the incident. Chief Contee says they'll be looking at that footage as part of the investigation and plan to release more details about what happened after reviewing it.