Massachussetts: Scientists questioning arson investigative practices that were used for years.
John Lentini, who has investigated more than 2,000 fires and become a national voice against poor fire investigative practices, said state investigators misinterpreted evidence that showed the fire probably started in the basement. “The government’s hypothesis of the way the fire spread violates the laws of physics,’’ he said.
For the past decade, fire scientists have been testifying in courts across the country, questioning old arson convictions with new science. The movement has launched a high-stakes battle, pitting scientists against prosecutors, who dispute the need for new trials.
In the past several months, three of the nation’s top fire scientists have questioned at least three Massachusetts arson convictions, including the 1983 life sentence for Victor Rosario of Lowell, the subject of a Globe investigation in June.
The scientists — fire engineers who scientifically test and study the outcomes of fires — say that years ago investigators regularly pointed to certain burn patterns as irrefutable evidence of arson. But scientific tests have since shown that those same patterns also appear in accidental fires.
Those misconceptions plagued most fire investigations before the field’s first scientific manual was published in 1991 and continued until the widespread adoption of the science a decade later, the scientists said.
Over the same period, the number of structure fires ruled arson in Massachusetts steadily declined.
From 1984 to 2001, the number of structure fires ruled arson fell more than 70 percent, while total structure fires remained largely stable.
In 1984, roughly 10,600 structures caught fire and investigators ruled 2,133 arson; in 2001, there were about 10,200 structure fires, of which 618 were ruled arson.
But the scientists said the decrease shows that as investigators used more science, they ruled fewer fires arson.
“There were a lot of accidental fires determined to be arson that weren’t,’’ Lentini said. “I don’t know any other way to interpret this dramatic of a decline.’’
Link:
http://www.boston.com/news/local/massachusetts/articles/2010/09/08/scientists_challenge_massachusetts_arson_convictions/