In a comment to my post last night about a legal ethics dilemma, Dr. Bernstein asked:
it would seem that if Kunz and Coventry had notified Logan's lawyer after the jury decision, the decision might have been accepted for appeal, further criminal investigation with the new facts and perhaps the jury verdict overturnedThe good doctor brought to mind one of the fundamental misunderstandings most non-lawyers and the media have when it comes to the court process - just what exactly is an "appeal?"
In the media, and in most laypersons minds, an "appeal" is any court proceeding that happens after trial (or sentencing) where the losing party seeks to have the trial court's decision overturned. In fact, "appeal" is a legal term of art and applies only to a relatively limited type of proceeding.
An appeal, strictly speaking, is a review of the lower court's decision to see if legal error has occurred. It is based only on the record produced before the lower court. That means that a court in a direct appeal cannot consider new evidence or even old evidence that wasn't presented to the lower court. As a result certain issues cannot be addressed on appeal, ineffective assistance of counsel foremost among them.
When the word appeal gets thrown around in the press, particularly as it relates to death penalty cases, more often they're really talking about some type of collateral proceeding, usually a habeas corpus proceeding. After a criminal defendant has exhausted his direct appeals (to the US Supreme Court, if she desires), she can file what is technically a civil action challenging her conviction. Since that is a new proceeding, new evidence can be presented and a new record which can then be reviewed in an appeal of the court's decision. That's where issues like ineffective assistance of counsel or newly discovered evidence can be hashed out.
So, to finally answer Dr. Bernstein's question: probably not. On direct appeal, anyway, the court would be limited to the record created at trial, which did not include any evidence about Wilson's confession. It could have been developed in a habeas proceeding, but the same problems with privilege would apply there.