On April 28 by a vote of 7-2, the United States Supreme Court overturned a lower court ruling and granted a new hearing to Tennessee death row inmate Gary Cone because the state had withheld evidence from the defense. During his trial in 1984, Cone, a Vietnam veteran, presented an insanity defense, arguing that psychosis induced by his drug use negated his guilt. While the prosecution denied any evidence of Cone’s drug use and referred to his defense as “baloney,” police reports, FBI files and witness statements discovered in the district attorney’s files 10 years later confirmed Cone’s extensive drug problem. Cone petitioned state courts for a new trial in light of this new evidence, but his petitions were denied based on a ruling that he had already made a claim of withheld evidence on direct appeal and lost. Later, a federal District Court denied Cone’s habeas corpus petition on the basis that the matter had been adequately resolved under state procedural law and the federal court was thus barred from reviewing the merits of the claim. The U.S. Court of Appeals for the Sixth Circuit affirmed this decision and held that the new evidence, even if considered, would not have influenced the guilty verdict and was thus immaterial.

The Supreme Court, however, ruled that federal courts could review the adequacy of the grounds by which the state court had barred Cone’s claim of withheld evidence. Moreover, while the Supreme Court agreed with the lower courts’ assessment that the new evidence would likely not have influenced the jury’s guilt finding, they determined that these same “courts failed to adequately consider whether the withheld documents were material to Cone’s sentence.” Based on precedent, evidence is “material” if its presence creates a reasonable probability of a different verdict or sentence. Writing for the Court, Justice John Paul Stevens noted that “[b]ecause the suppressed evidence might have been material to the jury’s assessment of the proper punishment, a full review of that evidence and its effect on the sentencing verdict is warranted.” The case has been remanded to the federal District Court where it will be determined whether evidence suppressed by the prosecution during the original trial could have affected the outcome of the Cone’s sentence.

Cone’s case had been reviewed on different issues and denied relief on two other occasions by the Supreme Court. The original murder occurred in 1980. Justice Alito concurred in part and dissented in part. Justices Thomas and Scalia dissented.
(See Cone v. Bell, No. 07-1114 U.S. (April 28, 2009); see also Associated Press, Court rules for Tenn. death-row inmate, April 28, 2009). See Supreme Court.