Victor Aldana, 22, is accused of hitting Brian Hernandez-Chavez and his mother as they walked along Duke Street near I-395 on Sunday.
Aldana was driving west on Duke Street when his car swerved off the road and hit the mother and son, police said.
The boy was pronounced dead at the scene and his 31-year-old mother’s legs were both broken.
Police said Aldana was drunk at the time of the accident.
Aldana has been charged with manslaughter while driving under the influence, maiming (under the influence), reckless driving and operating a vehicle without a license, police said.
Aldana has been held at the Alexandria jail without bond. His bond hearing is scheduled for Tuesday.