In a 5-4 decision, justices ruled in the 17-year-old murder case that the lawyer for Ronald Rompilla had not properly investigated possible evidence of mental retardation, and they ordered a new trial for the defendant.
Rompilla, now 56, was convicted of robbing, stabbing and setting on fire a tavern owner in Allentown, Pa., in 1988. It was the second time in a week that the high court overturned a death row sentence, citing an inadequate trial.
In his appeal, Rompilla argued that public defenders were wrong when they failed to review records showing mitigating evidence of mental retardation and a traumatic upbringing, even after prosecutors warned that they planned to use the documents against him.
Writing for the majority, Justice David H. Souter sided with the defendant.
"We hold that even when a capital defendant's family members and the defendant himself have suggested that no mitigating evidence is available, his lawyer is bound to make reasonable efforts to obtain and review material that counsel knows the prosecution will probably rely on," Souter wrote.
The ruling is a defeat for death penalty advocates, who have pushed for less federal court review of capital trials. Under Chief Justice William H. Rehnquist, the conservative-leaning court has generally agreed, declining to overturn death sentences except when they are "objectively unreasonable" given all the evidence at trial.
In a biting dissent, Justice Anthony Kennedy argued that the 3rd U.S. Circuit Court of Appeals in Philadelphia was right to uphold a state ruling that the attorney representation was adequate. He reasoned that Rompilla's attorneys had reasonably relied on testimony from mental health experts and family members.
The majority ruling unreasonably imposes a requirement on cash-strapped attorneys to pore through reams of documents in death penalty cases, even after conducting scores of interviews, for fear of missing something marginally useful, Kennedy said.