http://www.newyorker.com/...
But, based on the evidence, he had little doubt that it was an accidental fire—one caused most likely by the space heater or faulty electrical wiring. It explained why there had never been a motive for the crime. Hurst concluded that there was no evidence of arson, and that a man who had already lost his three children and spent twelve years in jail was about to be executed based on “junk science.” Hurst wrote his report in such a rush that he didn’t pause to fix the typos.
High-ups and Gov Perry could have chosen to save this guy but they completely ignored the new evidence. Maybe at the time, Perry was working to establish himself as a tough guy.