The Supreme Court on Monday upheld a rape conviction over objections that the defendant did not have the chance to question the reliability of the DNA evidence that helped convict him.

The court's 5-4 ruling went against a run of high court decisions that bolstered the right of criminal defendants to confront witnesses against them.

Justice Clarence Thomas provided the margin of difference in the case to uphold the conviction of Sandy Williams, even though Thomas has more often sided with defendants on the issue of cross-examination of witnesses.

The case grew out of a DNA expert's testimony that helped convict Williams of rape. The expert testified that Williams' DNA matched a sample taken from the victim, but the expert played no role in the tests that extracted genetic evidence from the victim's sample.

And no one from the company that performed the analysis showed up at the trial to defend it.

The court has previously ruled that defendants have the right to cross-examine the forensic analysts who prepare laboratory reports used at trial.