Some law enforcement authorities rely on outdated and disproved theories to wrongly classify an accidental fire as arson, says the Chicago Tribune. In the second of a series on problems in forensic science, the paper says that veteran arson investigators are questioning the ability of some colleagues to determine accurately the cause and origin of fires. For decades, arson investigators relied on a collection of beliefs and folk wisdom that was accepted as truth. In the last 30 years, many of these have been exposed by research and laboratory tests as unclear or plain wrong. The problems plaguing arson investigations–untested theories, shoddy analysis and a resistance to rigorous review–echo those found in other areas of forensics. When experts overstate their findings or rely on outdated thinking, the pursuit of truth in the courtroom is subverted. In fire investigations, mistakes can lead to the belief that there is a crime when none was committed.
In 2002, arson was blamed for 350 deaths nationwide and the destruction of an estimated 45,000 structures. More than 16,000 people were charged with the crime. Prosecutors still seek to convict people based on theories that have been systematically debunked. At the same time, defense lawyers are reaching out to private fire consultants to conduct independent analyses. Gerald Hurst, a consultant based in Austin, Texas, estimates that thousands of fires have been misinterpreted in the last 50 years because of reliance on myths. “God knows how many innocent people have been convicted,” he said. “You’ve got tons of holdouts–good old boys who’ve investigated 5,000 fires and they are doing it the same way they’ve always done it.”