Scrutiny of arson cases highlights a tangle between science and supposition. And in Texas, the stakes are big. As of last month, 742 offenders were in state prisons for arson, and on average, 275 more are convicted of the crime each year.Students and attorneys at the Innocence Project of Texas have spent much of the summer vetting old Texas arson convictions, and this may well be the next major front beyond DNA for identifying old, false convictions.
Those numbers make the Beyler report all the more troubling, said state Sen. Rodney Ellis, D-Houston, who has pushed to create a commission in Texas to explore questionable convictions.
"As scientific methods improve," he said, "it's a distinct possibility that we're going to find more problems in the criminal justice system."
In addition to Willis and Willingham, fire experts point to at least three other Texas cases that relied on questionable theories to win convictions.
"Accidental fires being turned into arsons is going on all the time," said Gerald Hurst, a Cambridge-educated chemist who was the chief scientist for the nation's largest explosive manufacturer.
He has turned to investigating fires and has testified on behalf of some of the arson defendants. Hurst sees a fundamental problem: investigators – most of whom began as police officers and firefighters – have no science background. ...
John Lentini, an author of the definitive guideline to fire investigation, said that honest investigators will walk away from about one in five fires unable to determine a cause because the heat destroys evidence, oil-based materials leave patterns that can be misleading, and firefighting water contaminates the scene.
"But you turn up enough 'undetermined' and you'll lose your job," Lentini said. "If there wasn't a crime and if the guy who makes the call gets it wrong, then he sets in motion a chain of events that will run over an innocent person."
In addition, lore about how fires react becomes ingrained, and it takes a long time for debunked science to become accepted.
Hoppe usefully supplied these additional links as background: