JACKSONVILLE, Fla. -- Just over an hour after it began deliberations in charges in the drive-by shooting of a 13-year-old boy, a Duval County jury found Josef Williams guilty of first-degree murder and discharging a firearm from a vehicle.

Josef Williams was convicted of killing Radarius Jackson on April 16, 2006, as the victim was walking home from a teen club with his older brother and two friends.

"Oh dear God, I'm glad it's over," said the victim's mother, Kelsha Jackson, after the verdict was announced.

In closing arguments, prosecutors told the jury the bullet that killed Jackson might have been intended for Jackson's older brother because of an ongoing feud between him and Williams.

In the defense's closing argument, lawyers told the jury that Williams may not have been an innocent victim.

"Why did Radarius Jackson get shot not in the back, but at an awkward angle?" defense attorney David Taylor asked. "I argue to you that arguably he could have been turned because he could have been firing back."

The jury didn't buy that argument, and the implication angered Jackson's mother.

"He was a good child, so everything the defense said was not true," Jackson said. "They didn't know Radarius."

The state's star witness was Gregory Almon, Williams' best friend who police said admitted to being in the car when the shots were fired. He has pleaded guilty to second-degree murder in exchange for his testimony in this trial.

Earlier in the trial, Almon, 25, said he was driving the car the night of the fatal shooting.

"He rolled down the window... He started looking... He started shooting when the dudes (the group of boys walking) started pointing at the car," Almon said.

Afterward the shooting, Almon said he urged Williams to get rid of the gun.

Williams faces a mandatory sentence of life in prison on the first-degree murder charge. Formal sentencing will take place in January.