The Philadelphia Inquirer, Todd Buchanan, File) MAGS OUT; NO SALES; TV OUT; NEWARK OUT, Associated Press
FILE - In this undated file photo, Han Tak Lee gestures at an unknown location in Pennsylvania. A federal appeals court has granted another look at the evidence in the case of Lee who was convicted of killing his daughter in what authorities alleged was an arson fire two decades ago in eastern Pennsylvania. Defense attorneys and some arson specialists say that determination was made using what's now considered flawed science. The 3rd U.S. Circuit Court of Appeals on Friday, Jan. 27, 2012, granted 76-year-old Lee's request for an independent examination of evidence from the July 1989 fire that killed 20-year-old Ji Yun Lee at a religious retreat in the Pocono Mountains.

PHILADELPHIA — A federal appeals court has granted another look at the evidence in the case of a man convicted of killing his daughter in what authorities alleged was an arson fire two decades ago but which defense attorneys and some arson specialists say was a determination made using flawed science.

The 3rd U.S. Circuit Court of Appeals on Friday granted 76-year-old Han Tak Lee's request for an independent examination of evidence from the July 1989 fire that killed 20-year-old Ji Yun Lee at a religious retreat in the Pocono Mountains. Attorneys for Lee, who is serving a life sentence, has long argued that advances in fire investigation show that the expert testimony used to convict him was unreliable.

"If Lee's expert's independent analysis of the fire scene evidence — applying principles from new developments in fire science — shows that the fire expert testimony at Lee's trial was fundamentally unreliable, then Lee will be entitled to federal habeas relief on his due process claim," the court said.

Defense attorney Peter Goldberger, who appealed the case along with the Pennsylvania Innocence Project, said Saturday that the court "recognized that the Constitution protects against keeping someone in prison on the basis of scientifically invalidated opinion testimony."

"This is a giant step forward and we hope that step is on a path to freedom," he said.

Monroe County District Attorney E. David Christine Jr. told The Philadelphia Inquirer that he might ask the appeals court to reconsider or take the case to the U.S. Supreme Court.

The appeals court noted that a prosecutor had suggested that the evidence might not be available any longer, and the decision suggests that in that case a lower court could rule that the evidence should be assumed to have favored the defense.

Lee, an immigrant from South Korea who had a Manhattan clothing store, had taken his daughter to the Stroud Township retreat in hopes of easing her escalating mental problems. At trial, his attorney did not question the finding of arson but maintained that it was set by his daughter to kill herself, an idea that the family has rejected.

"I never killed my daughter. I never set the fire. I'm not the right person to be here," Lee, told The Associated Press through a translator during a 2006 interview at Rockview medium-security prison in central Pennsylvania. "This is not arson. This is an accident."

At the time, investigators believed that only arson fires burn down rather than up, burn quickly as opposed to slowly and burn hotter than natural fires. But the fire textbooks began to change after the discovery of the "flashover" phenomenon, in which fire reaches a certain temperature and then erupts in an entire room. Such a fire, specialists now say, can leave signs earlier thought to indicate arson, such as evidence of high heat, flames burning down from the ceiling and the kind of burn holes earlier interpreted as multiple starting points.

Some U.S. arson specialists have said they fear that such longstanding interpretations of evidence may mean that there may have been hundreds of wrongful arson convictions. One case that has come under scrutiny is that of Cameron Todd Willingham, who was executed in Texas in 2004. A panel of experts later hired to look at evidence in the case concluded that the fire that killed his children in 1991 was accidental. Courts in Texas had refused to consider Willingham's claims of innocence.

"There are many people serving long sentences for murdering family members in what may have been accidental fires," Goldberger said.

Pennsylvania courts have rejected the argument that the prosecution's case was built on faulty science.

The appeals court, however, said the commonwealth "has not offered any evidence supporting the validity of the old methodology and does not challenge the accuracy of (an affidavit by an expert witness testifying for Lee) which describes the developments in fire science since Lee's trial and explains that many of the scientific theories relied upon by the commonwealth's experts have been refuted."