Yes, right?

Well, maybe not.

Here's the story of the Troy Davis case:

Twenty years ago, a late-night scuffle broke out in a Burger King parking lot in Savannah. When Mark MacPhail, an off-duty police officer, tried to intervene, someone pulled a gun and killed the officer. Soon after, Sylvester "Red" Coles, came to the police with a lawyer, accusing Troy Davis of the shooting.

Witnesses say it was Coles, not Davis, who killed MacPhail, but once the man-hunt began for Davis, law enforcement officials wanted to believe he was the man responsible for the slaying, and pressured witnesses accordingly. At this point, most of the witnesses who testified at trial have signed statements contradicting their identification of the gunman. Other witnesses who fingered Davis have said they made their stories up, facing police threats.

What we're left with is a case in which a man was sentenced to death despite no physical evidence, based on the word of witnesses who have since recanted or contradicted their testimony.

What about the witnesses who say Cole shot MacPhail? They're anxious to say so, but their testimony was blocked by federal courts, citing a provision in the Antiterrorism and Effective Death Penalty Act.

Yesterday, in a 6-2 ruling, the Supreme Court took the highly unusual step of ordering the lower court to hear the new evidence.

Scalia dissented, writing:

"This court has never held that the Constitution forbids the execution of a convicted defendant who has had a full and fair trial but is later able to convince a habeas court that he is 'actually' innocent."

Justice John Paul Stevens responded to Scalia:

"Imagine a petitioner in Davis's situation who possesses new evidence conclusively and definitively proving, beyond any scintilla of doubt, that he is an innocent man….The dissent's reasoning would allow such a petitioner to be put to death nonetheless. The court correctly refuses to endorse such reasoning."

Stevens is right.  But here's the thing – so is Stevens.

A habeus corpus petition is a legal device that goes back to the Magna Carta.  It's what prisoners — particularly death row inmates — use when all their appeals have been denied.  Basically, it allows someone imprisoned for a crime to petition the court on the grounds that their incarceration is illegal or unconstitutional.  In effect, if the habeus petition is heard and granted, it amounts to another trial — another bite at the apple to prove one's innocence.

Traditionally, most habeus petitions aren't even heard, and when they are heard, the court considers the arguments, and usually denies a new trial.  That's because, in order to win, the petitioner must show some defect in the trial that led to conviction.  An incompetent lawyer, a bribed jury, etc.  In other words, the prisoner must show that he did not get his constitutional right to a full and fair trial.

Scalia's point here is well-taken.  Troy Davis got a full and fair trial.  Did the witnesses who pointed their finger at Davis lie at the trial?  Well, it would seem so, but that doesn't make the trial "unfair".  Why not?  Because Davis' lawyer got to cross-examine those witnesses, try to expose them as liars, etc.  He failed, but that doesn't make the trial unfair or unconstitutional.

So yes, believe it or not, "actual innocence" is not an independent ground for a new trial. 

But of course, "actual innocence" can only be determined by a new trial in the first place.  Catch-22.

It should be noted that, by the strict letter of the law, Scalia is right.  The constitution does not protect an obviously innocent man who got a fair trial and was found guilty.

Stevens and the other five judges in the majojrity are, strictly speaking, going beyond the letter of the law, expanding the scope of habeus review, and allowing a hearing on whether this guy should get a new trial.  They are invoking humanity.  Or reason.  Or both.  They're not saying he's innocent; they're just saying that he has a right to have the new evidence considered so that a court could order a new trial.

Any way you look at it, it is an interesting development in habeus jurisprudence.