When Texas Gov. Rick Perry abruptly replaced four members of a state panel investigating flaws in forensic science a few weeks ago, he cast a shadow over one of the most important criminal justice reforms the state has seen in recent years. It's not too late to set things right.

Before Perry interfered, the Texas Forensic Science Commission was deep into an investigation of the arson evidence used to convict Cameron Todd Willingham, who was executed in 2004 for allegedly setting a fire at his home that killed his three young daughters. Convincing evidence now shows that he was innocent, and serious questions about his guilt had been presented to Perry before he signed off on the execution.

Perry's reshuffling came just 48 hours before a scheduled public hearing where the commission was set to question an arson expert, whose independent evaluation found recently that the evidence used to convict Willingham was deeply flawed. The meeting was cancelled, and the commission now sits in limbo under the leadership of new chairman John Bradley.

Bradley will appear November 10 before a special hearing of the Texas Senate Criminal Justice Committee to answer legislators' questions about the status of the Forensic Science Commission's work and plans for continuing ongoing investigations. A group of more than 400 Texans -- including 15 people exonerated through DNA after spending years in prison for crimes they didn't commit -- sent a letter to Bradley yesterday, urging him to ensure that the commission's work continues. 

"Undue delay - much less a complete change of course - seems destined to sweep this investigation, Texans' faith in forensic evidence and our criminal justice system, maybe even jurors' willingness to convict, away with it," the letter reads, in part.

Even those unconvinced of Willingham's innocence have come out against Perry's interference with an objective, independent review of the science in the case. Dallas Morning News editorial writer Rodger Jones wrote in a column that he's not ready to conclude that Willingham was innocent, but that's all the more reason that Perry shouldn't have intervened in this crucial process.

John Jackson, who prosecuted Willingham and now serves as a state judge in Texas, has said he still believes Willingham was guilty. He told reporters, however, that Texas should review evidence like this before putting someone to death. "If there had been a stay of execution in this case, that would have allowed a panel of disinterested experts to look at the evidence. We could have figured out whether the guy needed another trial or not. Maybe," he said.

This isn't just about the Willingham case. The Forensic Science Commission was formed in 2005 to look into allegations of forensic misconduct or negligence. The commission's review of the Willingham case can also help determine whether other arson cases in Texas may have been tainted by faulty forensic work. Meanwhile, the commission is also reviewing forensics in other cases, including the wrongful conviction of Brandon Moon.

Before Perry replaced four members, the group was making real progress and serving as an example for other states (and the federal government) of how a science-based, independent entity could evaluate evidence to help make the criminal justice system more accurate and reliable. The experience of the last few weeks now shows why bodies like this must be independent of politics. This commission can -- and should -- still move forward with its investigation of Willingham and other cases.