(CNN) -- The family of a Texas convict executed for the deaths of his three daughters in a 1991 fire launched a new effort to clear his name Wednesday by asking the state parole board for a posthumous pardon.
Cameron Todd Willingham was put to death in 2004 for setting the fire that killed the girls: Amber, Karmon and Kameron. But three expert reviews have concluded Willingham's conviction was based on evidence of arson that was outdated, and his family has insisted on his innocence.
"An error was made, and it is not too late to clear it up," the family's lawyers wrote in a petition filed with the state Board of Pardons and Paroles in Austin. Willingham and his family "deserve more," and "perhaps more importantly, the State of Texas deserves more."
The board denied clemency for Willingham before his execution, dismissing the first of three reviews that questioned the arson finding at the heart of Willingham's prosecution. Two subsequent studies have reached the same conclusion, finding that most of the signs investigators looked for as proof the fire was deliberately set had been rendered obsolete by a series of studies in the 1990s.
The last study was produced for the Texas Forensic Science Commission, which began looking into the Willingham case in 2008. A subsequent shakeup of the commission by Texas Gov. Rick Perry, who allowed Willingham's execution to go forward, led to accusations that the governor was trying to derail the investigation.
Perry has called Willingham a "monster" whose conviction withstood every appeal. Police and prosecutors in Corsicana, where the fire occurred, also stand by their case. Willingham professed his innocence in his final statement, but his ex-wife has said he confessed to killing the girls before the execution.
A jailhouse informant who testified in his trial has recanted his statement that Willingham admitted to setting the fire, and a now-retired judge who sat on the state court that rejected Willingham's appeal has written that the execution was "a miscarriage of justice" for which he was partly responsible, the family noted in its petition.
The Forensic Science Commission's investigation effectively ended in 2011, when a state attorney general's opinion sharply restricted the panel's jurisdiction. Goldstein said going to the pardons board -- whose members are Perry appointees -- was "one of the last resorts" the family has, but added, "This is about righting a wrong."
"This isn't about finger-pointing. It's not about blaming anyone. It's about giving a man his good name back," he said. "He died with little else but his name, and we took that from him."
Harry Battson, a spokesman for the pardons board, said the agency's staff will review the petition, notifying trial officials and surviving victims and preparing a file for board members. Applications typically take three to four months to process, he said.