COLUMBUS, Ohio (AP) — Two decades ago, Michael Webb's 3-year-old son died in a fire that investigators say Webb set in a scheme to kill his family, collect the insurance and start a new life with his mistress.
Webb, now on Ohio's death row for murder, doesn't dispute the blaze was arson but denies starting the fire and says investigators using now-discredited methods came to the wrong conclusion about where in the house the flames broke out. He says the correct determination points to someone else as the culprit.
On Wednesday, the Ohio Parole Board will take up his plea for mercy in one of a series of cases around the U.S. that represent a new legal frontier: Defense attorneys are using advances in the science of fire investigation to challenge arson convictions, in much the same way they are employing DNA to clear those in prison for murder and rape.
Research in recent decades has challenged long-held assumptions about how flames spread and the tell-tale signs they leave.
"Our scientific understandings have improved in recent years, and the effect of that has to be to say, 'We've got some innocent people who've been declared guilty based on misunderstandings,'" said John Hall, director of analysis and research for the National Fire Protection Association.
For example, decades ago, it was common for investigators to conclude an accelerant like gasoline was used if a fire burned particularly hot. In fact, the new arson science has found no such correlation, experts say. Another mistaken assumption: A V-shaped pattern on a wall of a burned building is proof of arson. All it shows is where a fire started.
One of the biggest arson cases to come under attack is that of Cameron Todd Willingham, convicted in a 1991 fire in Texas that killed his three daughters. He was executed in 2004. But some experts since then have testified that the blaze was probably accidental.
The primary evidence against Willingham was the testimony of arson investigators for the state fire marshal's office, who said they found pour patterns and puddling on the floor. They said those were signs that someone had poured an accelerant throughout Willingham's home.
But Craig Beyler, chairman of the International Association of Fire Safety Science, wrote in a 2009 report that investigators did not have enough evidence to make an arson finding. He cited findings in the field of fire research that were arrived at since the 1991 blaze or became widely accepted after the original investigation.
For example, tests have found that pour-like patterns on the floor can occur because of radiant heat, even without accelerants, according to Beyler's report. Experiments have also found that melted plastics can create patterns that look like liquid spills, Beyler said.
In Ohio, Webb's chief argument is that a fire investigator wrongly concluded that the 1990 blaze started near a closet or a bathroom where Webb acknowledged he was standing.
In a report submitted on Webb's behalf earlier this month, Gerald Hurst, a chemist and fire investigator in Austin, Texas, said that based on gasoline-spill experiments conducted around the U.S. in the years since the crime, the origin of the fire could have been anywhere on the main floor.
That is important to Webb's case because of statements by one of his teenage daughters that she saw "a man in red" in the house the morning of the fire. Webb's attorneys argue that that person could have been the boyfriend of Webb's other daughter.
Webb's lawyers acknowledge Hurst's findings don't exonerate Webb, but say they raise enough questions to justify a new trial.
Prosecutors dismiss the "man in red" theory, saying the girl's statements varied, that no evidence implicating the boyfriend was found, and that the daughter could have actually seen Webb holding a red gas can. They say Webb is presenting nothing new.
Webb is making "a contention of innocence that is refuted by the hard evidence in the case," Clermont County prosecutors said in their filing with the parole board.