Police responded to the scene in the 9900 block of Greenbelt Road around 8:10 a.m., and found 39-year-old Bryan Pailin of Morningside suffering from gunshot wounds.
Pailin was taken to a local hospital, where he was pronounced dead.
Dominick Pailin, 29, was taken into custody after he allegedly admitted to shooting his brother during an on-going dispute.
Police charged him with second-degree murder, and other, related charges.
If you have any information that might help investigators, call (301) 516-2512.