The report examined prosecution arson testimony in the trials of two men: Ernest R. Willis, convicted of killing two women in a house fire in 1986 in Iraan, and Cameron T. Willingham, convicted of burning his home in Corsicana in 1992, killing his three young daughters.
Mr. Willingham was executed by lethal injection on Feb. 17, 2004, after Gov. Rick Perry rejected a plea for a last-minute stay, once the courts and the State Board of Pardons and Paroles had declined to intervene.
Mr. Willis was exonerated and pardoned on Oct. 6, 2004, and collected almost $430,000 for 17 years of wrongful imprisonment.
The report says that prosecution witnesses in both cases interpreted fire indicators like cracked glass and burn marks as evidence that the fires had been set, when more up-to-date technology shows that the indicators could just as well have signified an accidental fire. In one case, the signs were accepted as proof of guilt, the report said; in the other, they were discarded as misleading.
"These two outcomes are mutually exclusive," Mr. Scheck said. "Willis cannot be found 'actually innocent' and Willingham executed based on the same scientific evidence."