SCOTUS heard arguments about the constitutionality of a South Carolina rule that barred a condemned man from introducing evidence pointing to another possible suspect.
In the case at issue, the South Carolina Supreme Court upheld Holmes' conviction in 2004 and said it was appropriate to exclude evidence suggesting another man was the killer. Its 4-1 decision applied a state standard, developed in two previous South Carolina cases, that said a judge can disallow presentation of evidence against a third party when there's strong evidence against the defendant on trial.
The Mercury News has this article on the arguments before SCOTUS.
The Christian Science Monitor has this article on the case.
The Guardian has this article.