Nathan Curtis, 50, of Choctaw County has been charged with shooting his father. The father's girlfriend was also injured.
The shooting happened around 8 a.m. Saturday in the victim's driveway.
Choctaw County Sheriff Tom Abate says the shooting is the result of a dispute over hunting.
"We believe that the father and son were arguing over some hunting rights on some land and it went bad from there," said Abate.
Investigators say Nathan Curtis fired bird shot from a shotgun into the truck where his father and his father's girlfriend were sitting.
"He was allowed to hunt on a grass patch," said Abate. "He brought some friends over and Mr. Ollie didn't want those friends to hunt on it. He just wanted his son to hunt and not anybody else."
Investigators say the gunman was likely an arm's length away when he fired the shotgun into the driver's side window.
Ollie Curtis, age 74, was shot in the side of his chest; his 72-year-old girlfriend, Clozell Ruffin Tucker, was wounded by shotgun pellets.
According to witnesses, after the shooting the suspect fled the scene riding a four-wheeler.
"He ditched the shotgun in the woods, which was later recovered by deputies," said Abate. "Then, the four-wheeler was also ditched in a different location in the woods and recovered."
About an hour after the shooting, the suspect returned to the scene where he surrendered to authorities.
Sheriff Abate says the shotgun used was stolen from Lauderdale County, Miss.
"In the past he has made other threats to other people," the sheriff said. "He's a convicted sex offender somewhere up north."
For now Nathan Curtis remains jailed. Bond has not yet been set.
The elder Curtis and Tucker remain hospitalized in Birmingham.
Nathan Curtis is accused of attempted murder, assault in the first degree, shooting into an occupied vehicle and receiving stolen property.