Balko reports a pattern:
In the Hank Skinner case, Perry has actively fought DNA testing that could confirm the innocence (or guilt) of another Texas man on death row. Skinner was at one point hours from execution before the Supreme Court intervened (the intervening justice was Antonin Scalia, believe it or not). In Skinner’s case, the prosecution actually began to conduct DNA testing on crime scene evidence, then stopped when the first tests confirmed Skinner’s version of events. Perry again justified willful ignorance in this case by simply noting that he’s personally convinced of Skinner’s guilt.
Details on the Cameron Todd Willingham case here.
The Dish 