Officers were called to the 7700 block of Annapolis Road around 11:30 a.m. Thursday for a welfare check.
Upon arrival, police found 27-year-old Armando Cousins-Stoute, who had no fixed address, suffering from a gunshot wound. He was pronounced dead at the scene.
Homicide Unit detectives are working to determine a motive and identify the person or people responsible.
Authorities are offering a reward of up to $25,000 for information that leads to an arrest and indictment in this case.
Anyone with information is urged to contact the Homicide Unit by calling (301) 516-2512.
This is a developing story. Stay with Daily Voice for updates
Want breaking news in the DMV as it happens, or want to contribute? Join the DMV All Incidents Facebook group.
Click here to follow Daily Voice Olney and receive free news updates.