WASHINGTON (CNN) -- An imprisoned killer who was 12 years old when he committed a double murder, and then was given a 30-year sentence, was denied a hearing by the Supreme Court Monday.
Christopher Pittman, center, killed grandparents Joe Frank Pittman , left, and Joy Roberts Pittman.
Christopher Pittman's defenders argued the sentence was excessive for someone that age and claim heavy doses of antidepressants he was taking at the time sent his mind spinning out of control.
Now 19, Pittman was convicted three years ago of killing his grandparents with a shotgun as they slept, then setting the house on fire.
The county prosecutor in South Carolina argued it "was as malicious a murder as you're ever going to find."
The justices, without comment, refused to intervene. At issue was whether the state properly used its discretion to try Pittman as an adult, whether the sentence was excessive, and whether mitigating factors should apply.
Outside a death-penalty context, the high court has offered little recent guidance on how to treat underage defendants.
Pittman's lawyers argued no other inmate in the United States is serving so severe a sentence for a crime committed at such an early age.
The inmate's legal team, from the University of Texas Law School, expressed disappointment at the high court's refusal to accept the case.
Michele Deitch, an attorney and adjunct professor, speculated the justices may "have recognized a growing national trend against sentencing young children to harsh mandatory terms in prison, and wants to give state legislatures the opportunity to correct this problem before it rules on the issue."
Deitch and other lawyers worked on the case for free, since Pittman could not afford to pay the extensive legal costs.
Pittman, now 6 foot 2 inches tall, works grounds maintenance at an adult correctional facility outside Columbia, South Carolina. He received a GED high school equivalency in 2006.
With the high court's denial of his appeal, Pittman has few legal options to have his sentence reduced. Under his current sentence, he would be released from prison in his mid-40s. He has a separate civil lawsuit against the state, alleging his court-appointed trial lawyers were ineffective.
At the time of the crime, the boy had bounced around homes for years, experiencing a half dozen family splits and divorces after his mother had twice abandoned him as a child. She has not been in Pittman's life for years.
Joe Pittman, the boy's father, raised Christopher Pittman and his sister for much of their lives, but the relationship between father and son deteriorated. A state psychologist later testified this was a "young man who'd had difficulty with the adults in his life."
After threatening to harm himself and suffering other emotional incidents, the boy was diagnosed as clinically depressed. His lawyers said Pittman was then given Paxil, a mild antidepressant no longer recommended for those under 18.
In the midst of these episodes, the youngster was allowed to live temporarily with his paternal grandparents in Chester County, about halfway between Columbia, South Carolina, and Charlotte, North Carolina. The family said Joe and Joy Pittman had been a source of stability for young Christopher earlier in his life.
On November 28, 2001, Pittman was sent home early for fighting in school and sent to bed by the grandparents. The boy claimed his "Pop-Pop" also beat him with a belt as punishment.
Christopher later admitted taking a pump-action shotgun and shooting his grandparents to death in their bedroom shortly before midnight. Prosecutors said he then set the house on fire to cover his tracks, took the family SUV, his golden retriever and a cache of weapons, and fled.
He was arrested hours later on a remote gravel road in a nearby county.
Just days before, a doctor had begun prescribing Zoloft, another antidepressant. The family contends the abrupt substitution of drugs caused a bad chemical reaction, triggering violent outbursts.
At trial, a parade of psychiatrists offered conflicting testimony on whether the boy's emotional problems excused his criminal behavior. Prosecutors called the Zoloft defense a "smokescreen."
The jury took less than a day to find Pittman guilty. Because he had been transferred from juvenile to adult court, the judge was not allowed to take his age into account at sentencing. Pittman received the shortest possible term for murder, 30 years without parole.
Juror Steven Platt later told CNN the crime appeared deliberate. "It always seemed like the defense was grasping at straws," he said. "Just because you take prescription medicine doesn't mean you can't be held accountable for your actions."
Pfizer, the maker of Zoloft, would not comment on the current appeal, but said after the verdict the drug "didn't cause his [Pittman's] problems, nor did the medication drive him to commit murder. On these two points, both Pfizer and the jury agree."
The Food and Drug Administration in 2004 ordered Zoloft and other such medications to carry warnings of an increased risk of suicidal behavior in children.
Pittman's sister, Danielle Pittman Fincher, said afterward, "I know for a fact that there is absolutely no possible way my brother in his current state of mind could have done something like that."
South Carolina officials refused a CNN request to interview Pittman behind bars. And state prosecutor Barney Giese's office would not comment while the appeal was pending.
The Supreme Court in 2005 banned the death penalty for underage killers. The justices in that case cited evolving "national standards" as a reason to ban such executions.
Among Pittman's defenders is his maternal grandmother, Delnora Duprey, who travels from her central Florida home once a month to visit Pittman on weekends. She describes a young man who, despite his situation, is coping remarkably well.
"He's working ahead with his life, taking classes," Duprey told CNN recently. "He doesn't feel sorry for himself, but he'd like a chance at moving out of prison and getting a new start for himself."
Along with a network of friends and pro bono lawyers from the University of Texas Law School, Duprey is critical of South Carolina's decision to hold the boy for more than three years before trial, much of it in prisons they say were inappropriately dangerous for someone Pittman's age.
Attorney Michael Sturley said 41 states do not punish 12-year-olds as South Carolina does. And none has allowed as harsh a sentence as Pittman was given.
"There are no 12-year-old monsters," said Duprey. She said Pittman recently told her, " 'Grandma, I think God forgives me. Nana and Pop-Pop' -- that's what he called them -- 'forgive me. But I don't think I'll ever forgive myself.' "
There was no immediate comment from Duprey or Pittman's lawyers to the denial of his Supreme Court appeal. E-mail to a friend