Marietta police, meanwhile, responded to a report of someone with a gun, police said.

Christian's friends said the officers surprised them and came on the scene waving guns.

"Nobody knew the police were coming," one of Christian's friends, Kenny Drake, said. "All they said was, 'Freeze!' One told me, 'You move, I shoot.' "

Two of the teens tried to flee, but Dwayne Conley, 14, said he stopped when an officer drew a gun on him.

Christian continued to run for another 20 yards, went around the corner of a nearby building and was shot by two officers, Drake said.

"When he went around the building, I heard him screaming for a good three seconds," Drake said. "Then it just went quiet."

Police said the officers on the scene believed Christian's pellet gun to be a Beretta .22-caliber semi-automatic pistol. "It looks like your standard automatic weapon," police spokesman Mark Bishop said.

Witnesses said Christian tried to tell police the gun was only a toy.

"He told the police, 'Don't shoot. It's a fake gun,' " said Caliph Hudson, who watched the incident from his apartment window.