Witnesses said a fistfight preceded the shootings Saturday evening.
The victims, identified as Kevin M. McCann, 23, of Chicago, and Marine 2nd Lt. Brett Johnson Harman, 23, of Park Ridge, Ill., were tailgating before North Carolina State University's season-opening football game against Richmond. Neither was a student at the university.
Tony Harrell Johnson, 20, of Raleigh, and his brother, Timothy Wayne Johnson, 22, an NCSU student, were arrested a short time later and charged with two counts of first-degree murder, said sheriff's department spokeswoman Phyllis Stephens.
A first appearance hearing for Timothy Johnson was scheduled for Tuesday, Stephens said. Information about Tony Johnson's first hearing was not immediately available.
Because of the Labor Day holiday, their earliest court date would be Tuesday.
A witness, Brian Smith, 31, said the victims had been tossing a football when a car drove recklessly in a parking lot packed with football fans. He said the men pulled the blond-haired driver from his car and beat him, pushing his head into the dirt.
The blond man left in his car, shouting curses and threatening revenge, Smith said. He returned later and asked Smith where to find the men who had beaten him, saying he had "a .38 Smith & Wesson for them."
Smith, who said the man appeared intoxicated, pointed in the direction of the victims and heard gunshots a short time later.
Smith ran to the shooting scene and found one victim wounded in the face, the other in the upper torso.
"My reaction is that I got two guys killed," Smith said.
The second suspect drove the gunman from the scene, Smith said.
Witness Jason Seaton, 32, said he was standing less than 30 feet away when he saw two young men get out of a car and walk up to a small group of tailgaters.
Seaton said he then saw a puff of smoke and heard what he thought sounded like a series of bottle-rockets.
"I saw the two guys, and they weren't sprinting out of there," he said. "They were all nonchalant jogging out of there."
Seaton said he found the two victims on the ground and used two of his shirts to try to stop the bleeding. But it was too late for one of them.
"I saw him gasp three times, and he was dead," Seaton said. "When I get out of here, when nobody's looking, I'm gonna cry about this."
The second victim died at a hospital.