The bloodshed occurred in Arkabutla, a rural hamlet of fewer than 300 people in Tate County in northern Mississippi, about 40 miles (60 km) south of Memphis, Tennessee.
The gunman, identified as Richard Dale Crum, 51, was charged with first-degree murder, Tate County Sheriff Brad Lance told reporters.
"Jill and I are mourning for the six killed in today's violence in Tate County, Mississippi - as we have for far too many Americans," Biden said in a statement, referring to his wife.
[1/4] A man stands next to the vehicle of the victim of a shooting outside a gas station convenience store in Arkabutla, Mississippi, U.S. February 17, 2023.
Deputies recovered a shotgun and two handguns from the suspect, Lance said.