WHAT RICK PERRY DOESN’T WANT TO KNOW…. In last month’s issue of the New Yorker David Grann considers the case of Cameron Todd Willingham, and makes a very compelling argument that Texas executed an innocent man five years ago.

Texas Gov. Rick Perry (R), who was governor when Willingham was killed by the state, doesn’t want to hear exculpatory evidence, and has taken steps to make sure no one else hears it either. (thanks to reader V.S. for the tip)

Gov. Rick Perry replaced the chairman and two members of the state’s Forensic Science Commission, two days before the commission was to hear evidence that Texas executed an innocent man. The new chairman canceled the hearing, at which an arson expert was to present a report critical of the arson analysis that led to the conviction of the man, Cameron T. Willingham. Mr. Willingham, above, was executed in 2004 after being convicted of setting a 1991 fire in which his three children died. Governor Perry, who was in office at the time of the execution, has expressed confidence in Mr. Willingham’s guilt.

“This is like the Saturday night massacre,” said Barry Scheck, co-director of the Innocence Project, which has been working on the case. “It’s like Nixon firing Archibald Cox to avoid turning over the Watergate tapes.”

When Willingham was convicted, prosecutors relied heavily on an “expert” that testified about the origins of the fire that killed Willingham’s daughters. The problem, we now know, is that the “expert” apparently didn’t know what he was talking about.

The Forensic Science Commission, created to consider the competence of those who offer forensic testimony, hired Dr. Craig Beyler, an actual arson expert, to consider the evidence and report on his findings. He was scheduled to discuss what he found tomorrow.

Apparently worried about what the facts might show, Perry intervened, got rid of some of the Forensic Science Commission’s members in the 11th hour, and ensured that the commission couldn’t hold a meeting to discuss the Willingham case.

The meeting with Beyler to evaluate the science has been cancelled — and hasn’t been rescheduled. The evidence that Texas killed an innocent man will wait indefinitely.

For his part, the governor said the fired commission members’ terms were nearly complete and his move was “pretty standard business as usual.” Perry did not, however, explain why the commissioners had to be fired 48 hours before an important meeting, and why other commission members had their terms renewed but these three had to be replaced immediately.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.