South Carolina Criminal Defense Blog

in State v. Mercer, the S.C. Supreme Court holds that it is "clear error" for the trial judge to exclude testimony that a Spect scan revealed an abnormality in the defendant's brain during the penalty phase of a death penalty trial. It was, however, harmless error in this case.

A. “Spect Scan”

Dr. Steedman is a medical doctor who is board certified in neurology and psychiatry. Dr. Steedman analyzed a “SPECT Scan” conducted on Mercer’s brain.[6] The SPECT Scan was initially reviewed by a radiologist who noted a “questionable abnormality.” Dr. Steedman was prepared to render a stronger finding of an abnormality. The State objected strenuously against such testimony, claiming surprise and prejudice. After an offer of proof and lengthy discussion, the trial court sustained the objection on the basis of Rule 403, SCRE, and a so-called “discovery order” violation. This ruling rises to the level of an abuse of discretion.

Application of Rule 403 should be cautiously invoked against a capital defendant in the penalty phase, especially in light of the due process implications at stake when a capital defendant seeks to introduce mitigation evidence.[7] The probative value of Dr. Steedman’s excluded testimony was, as a matter of law, not substantially outweighed by its potential for prejudice, as a result of the purported late disclosure or otherwise. Reliance on the so-called “discovery order” cannot withstand even minimal scrutiny, for there was no formal discovery order.[8] In any event, Dr. Steedman was disclosed to the State, as was the general substance of his testimony.

Despite the fact that the Court found the error harmless in this case, this language shows the advances that courts have made in accepting testimony regarding brain science and the impact it has on sentencing issues. It was harmless error because, although some of Steedman's testimony regarding the abnormality was excluded, there was already testimony admitted about the Spect scan, the abnormality, and Mercer's cognitive defects.

The Court upheld the conviction and death sentence, holding that the trial court did not abuse its discretion in excluding a juror as not death-qualified, in excluding testimony of Mercer's co-defendant's lawyer, in preventing Dr. Steedman from offering expert psychiatric testimony, in denying a post-trial motion for additional funds to test the co-defendant's gloves for gun shot residue, or in denying a post-trial motion for a new trial based on after-discovered evidence that the co-defendant had confessed to a cell mate that he had committed the murder and not Mercer.