When Carolyn Muncey's body was found in the woods near her home in rural Union County, Tenn., it didn't take police long to finger a suspect.
Paul House had a prior conviction for aggravated sexual assault and prosecutors later told the jury at his murder trial that investigators found his semen on Mrs. Muncey's clothing. Mr. House was convicted and sent to Tennessee's death row to await his execution.
There was just one problem - the semen belonged to the victim's husband, whom defense lawyers say is the actual killer.
Now 20 years after his murder conviction, House's case arrives Wednesday at the US Supreme Court where the justices are being asked to decide how federal courts should weigh scientific evidence - like DNA test results - when considering whether to grant a convict a new appeal even after all allowable appeals have been exhausted.
The case, House v. Bell, is important because it marks the first time the justices have agreed to examine a case involving post-conviction appeals based on DNA testing. The technology has proved efficient and reliable in identifying innocent defendants who have been convicted and imprisoned. But analysts say that technology may go for naught in many cases unless the high court explicitly recognizes the value of science-based evidence, even long after the crime has taken place and all appeals have been used up.
Last week, Virginia Gov. Mark Warner ordered new DNA tests in the case of a convict who had already been executed. If the they absolve Roger Keith Coleman of a 1981 rape and murder, it would be the first time in the United States a person has been exonerated by scientific testing after his execution, death- penalty opponents say.
"What we have learned at the Innocence Project is that DNA evidence 10, 20, 30 years later turns out to be much more reliable than eyewitness testimony and more reliable than confessions that are often false," says Peter Neufeld, a New York-based lawyer and cofounder of the Innocence Project.
Since 1989, the Innocence Project has used DNA testing to win 172 exonerations - including 14 on death row. Project founders Barry Scheck and Mr. Neufeld filed a friend of the court brief urging that House be granted a new trial.
"Whenever post-conviction DNA testing proves that a prosecutor's theory of the case was false and proves that certain factual assertions present in the original trial were false, then at a minimum that conviction should not stand and a new jury should be able to hear the truth," says Neufeld.
In some cases, the DNA testing provides such powerful evidence of innocence that it compels dismissing all charges, he says. But in other more murky cases, like the House case, he says judicial hands should not be tied by procedural prohibitions against additional appeals.
House's lawyers say police used sloppy procedures and got the wrong man. They say at a minimum the courts should give him a new trial.
Lawyers for the state say that even though mistakes may have been made, the balance of evidence still points to House as the murderer. They add that he has already been afforded all the appeals the law permits.
Fifteen states filed a friend of the court brief asking the high court not to make it easier for federal judges to order new trials in state cases whenever new DNA or other scientific tests undercut some or all of the evidence at trial. The states argue that their own courts are capable of dealing with claims of actual innocence.
The House case arises amid a backdrop of legislative and other efforts to limit post-conviction appeals to those who can make a particularly strong case of their innocence, says Kent Scheidegger, legal director of the Criminal Justice Legal Foundation. Mr. Scheidegger did not file a friend of the court brief in the case because he says he doubts it will become an important precedent: "It may be a vehicle for incremental change, but I do not expect anything groundbreaking out of this case."
Neufeld has a different view. He says DNA testing has shown that innocent defendants are being convicted in much higher numbers than anyone expected. "For the first time the entire American public, including the nine Supreme Court justices, are aware of just how vulnerable our criminal justice system is and how easy it is for innocent people to get wrongly convicted," he says. "If there is going to be a situation where we are going to go back and give somebody a second trial, then it should be in those cases where scientific evidence sheds new light on the question of guilt and innocence."
• Material from the Associated Press was used in this report.