In fact, the prevailing attitude seemed to be that letting any unreliable evidence into trials doesn’t matter too much, because juries will sort it all out. The Justices have in their hands an expert affidavit from the American Psychological Association that explicitly states: “juries tend to ‘over believe’ eyewitness testimony”. But the Court still seemed to oppose what Justice Kennedy called “invading the province of the jury.”
It is a given that our jury system is fundamental to assuring fair trials, but juries do get it wrong (over 75% of 275 wrongful convictions uncovered by DNA testing were due at least in part to mistaken eyewitness testimony which jurors believed). And lives are at stake.
In the case of Mr. Perry in New Hampshire, the crime was a relatively mild one – theft. But for Troy Davis, the unreliable eyewitness testimony “staged” by Savannah police was thoroughly and whole-heartedly accepted by the jury, could not be overcome on appeal (because recanting witnesses are unreliable!), and was ultimately instrumental in his execution by the state of Georgia. Three of the original jurors had urged the state not to carry out the execution, but this time they were ignored.
The Court is expected to rule on the Perry case sometime next year.