Gov. Rick Perry replaced the chairman and two members of the state’s Forensic Science Commission, two days before the commission was to hear evidence that Texas executed an innocent man. The new chairman canceled the hearing, at which an arson expert was to present a report critical of the arson analysis that led to the conviction of the man, Cameron T. Willingham. Mr. Willingham, above, was executed in 2004 after being convicted of setting a 1991 fire in which his three children died. Governor Perry, who was in office at the time of the execution, has expressed confidence in Mr. Willingham’s guilt. “This is like the Saturday night massacre,” said Barry Scheck, co-director of the Innocence Project, which has been working on the case. “It’s like Nixon firing Archibald Cox to avoid turning over the Watergate tapes.” But a spokesman for the governor, Chris Cutrone, said the governor’s decision was “business as usual.” “Some people’s terms expired,” Mr. Cutrone said, “and we reappointed new people.”

Image Cameron Todd Willingham was executed in 2004.