COLUMBIA -- Prosecutors have filed a scathing appeal asking a South Carolina judge to reconsider his ruling granting a new trial to a man who was convicted of killing his grandparents when he was 12 years old, then blamed the antidepressant Zoloft for the crime.

Circuit Judge Roger Young of Charleston ruled in July that Christopher Pittman deserved a new trial because his attorneys didn't pursue a plea deal and focused too much on Zoloft.

In its appeal, the state attorney general's office said defendants have no right to a plea deal if prosecutors don't want to offer one and Pittman's lawyers knew the so-called Zoloft defense was risky.

"The state would respectfully assert this court should reconsider its ruling, deny relief, and not allow this case to run afoul of the maxim that decisionmakers should not allow hard cases to make bad law," Assistant Attorney General Creighton Waters wrote.

Pittman, now 21, was tried in Charleston as an adult in the 2001 shotgun deaths of his grandparents in their Chester home. He was convicted in 2005 of murder and sentenced to the minimum of 30 years in prison.

Waters also pointed out that Pittman's family sought out Andy Vickery, an attorney who mostly handled civil cases and specialized in taking on drug companies over antidepressants. Young's ruling suggested Vickery didn't understand South Carolina law and was so determined to harm Zoloft's maker that he ignored what was best for Pittman.

Prosecutors said Vickery had already unsuccessfully defended a man convicted of five counts of murder who blamed antidepressants and Pittman's family knew that when they asked him to join the defense team.

"The 'Zoloft defense' was not driven by Vickery for his own gain," Waters wrote. "It was in existence long before his involvement and was why he was contacted in the first place -- not the other way around."