HOUSTON (October 28, 2009)—The Houston Chronicle and its owner Hearts Newspapers LLC filed suit Tuesday in an attempt to force Texas Gov. Rick Perry to disclose a clemency report he received before denying a stay of execution for death row inmate Cameron Todd Willingham, whose conviction for killing his three daughters has been called into question because of what experts say was the faulty evidence used to convict him.

Texas put Willingham to death in 2004 for the 1991 deaths of his three children, whose bodies were found after a fire at the family's home in Corsicana.

Several experts now say the evidence that investigators used to support the contention that Willingham set the fire deliberately was flawed, but Corsicana officials, Perry and even the lawyer who represented Willingham at trial maintain that the fire was set on purpose and that murder was the motive.

The catalyst for the controversy over Willingham’s conviction and execution is a report released in August from an independent expert hired by the state that mirrors the 2006 findings of fire investigation experts hired by the Innocence Project.

Fire scientist Craig Beyler wrote in the new report requested by the Texas Forensic Science Commission, "the investigators had poor understandings of fire science."

The Forensic Science Commission agreed in August 2008 to review investigators' conclusions that Willingham set the fire at his family's home in Corsicana two days before Christmas in 1991, but Gov. Rick Perry removed three members of the panel days before it was to have met to discuss the findings.

Trial evidence suggested an accelerant was used to start the deadly fire, but the Innocence Project says experts in a report it commissioned concluded the fire was not intentionally set.

Willingham was arrested and charged on Jan. 8, 1992, two weeks after the three girls died.

Evidence at his trial showed an accelerant, believed to be charcoal lighter fluid, was used to ignite the floors, a front threshold to the house and on a concrete porch, and neighbors testified they saw Willingham outdoors even before the flames engulfed his home.

Witnesses said he showed no grief over the deaths, but instead was upset about his car and a dartboard

One of the prosecutors called Willingham a sociopath whose children were an impediment to his lifestyle.

Willingham insisted in a death row interview that he was innocent and that his trial was a joke.

Willingham initially told investigators the fire started as he and his children slept, but Corsicana investigators found evidence the fire was set deliberately with a flammable liquid.

Amber Louis Kuykendall, 2, and twins Karmon Diane Willingham, 1, and Kameron Marie Willingham, 1, died in the fire.

Willingham's wife, who was out shopping when the fire broke out, initially supported her husband's version that a lantern must have fallen, igniting the fire, but Stacy Kuykendall later told the Corsicana Daily Sun she no longer believed her former husband's story.

Earlier this month, the City of Corsicana released a sworn affidavit that says Willingham’s wife told relatives that Willingham confessed to her days before his execution that he set the fire that killed the couple’s three daughters.

Ronnie Kuykendall, whose sister Stacy was married to Willingham at the time of the deadly fire in 1991, told investigators that Stacy visited Willingham on death row about a week before his execution and later told relatives said that Willingham told her “he had set the fire because he knew that she was going to leave him…and he figured that if he did this, she would stay with him and she could get her tubes untied and they could start another family.”

The city also released an affidavit from a witness to the fire who said he saw Willingham pack his car and move it out of the carport, even as smoke poured from the house.