Updated

The family of a man executed for the deaths of his three daughters in an arson fire, based on what scientists now say was faulty evidence, petitioned the Texas Board of Pardons and Paroles on Wednesday to formally review the case.

Lawyers for Cameron Todd Willingham's stepmother and cousins submitted thousands of pages of documents they say rebut all the evidence presented at Willingham's trial and asked the board to issue a posthumous pardon. The board meets Thursday and had no immediate comment on the case.

A fire destroyed Willingham's home in 1991 and killed his three daughters. A state fire marshal who studied the scene testified at Willingham's 1992 trial that the fire was arson.

Scientists have since refuted much of the methodology used by arson investigators before 1992, including the techniques used by the fire marshal in the Willingham fire. Attorneys submitted the new scientific findings to Gov. Rick Perry in 2004 and asked for time to reopen the case, but Perry allowed Willingham's execution to go forward that year. Willingham maintained his innocence until his death.

The state fire marshal's office stood by their findings in the case until 2011, when the Texas Forensics Commission ruled the methods used were profoundly scientifically flawed.

"I promised (Todd) we would not falter on our commitment to exonerate him, and by doing so, he and the rest of the family could find peaceful closure," said Judy Cavnar, Willingham's cousin. "I further believe Todd expected us to expose the outdated scientific methods used in processing the evidence, the same evidence that plagues so many cases and sent him to a premature grave."

The Texas Forensics Commission last year recommended a review of all arson convictions based on the same science used to convict Willingham. The recommendation came after the state attorney general limited the scope of its investigation into Willingham's case, prompting the panel to decline to issue a finding on any alleged negligence or misconduct by the State Fire Marshall's Office in the case.

The forensics commission previously determined the techniques used to convict Willingham were flawed, such as the belief that crackling of windows is an indication of arson. Scientists now know the crackling happens when firefighters spray cold water on them.

Gerry Goldstein, the attorney for the family, said the report submitted Wednesday to the Board of Pardons and Paroles uses the latest science to prove every indicator used by the fire marshal to prove arson in Willingham's case actually proves the fire was accidental.

"This is not like a witness who forgot something, this is like DNA. This is science," Goldstein said.

Also speaking in support of the family Wednesday was Ernest Willis, who spent 17 years on Texas' death row for a similar arson conviction and spent time with Willingham in prison. Willis' attorneys convinced the district attorney in his case to help exonerate him after experts refuted the old arson evidence. The state released Willis one month after Willingham's execution.

"I got lucky, I got a big firm out of New York ... that spent 12 long years and spent $5 million on experts and that's what this is all about, money and politics," Willis said. "Gov. Perry needs to step forward and give this family some relief."

State officials currently are reviewing 26 arson cases for possible false convictions based on the same evidence.

Goldstein also called on lawmakers to consider making the parole and pardon system more transparent. The board is up for legislative review next year.