In a September letter to the Los Angeles Police Department crime laboratory Robin W. Cotton, a director of technical forensic science for Cellmark, wrote that when a control test showed an "imperfect" profile and should have been reanalyzed, Blair instead substituted a control profile with no imperfections. The letter stated that all of the affected cases have been re-tested, and the results of the original analysis remained the same.

Defense lawyers are particularly upset because they really have no way of knowing if tests are manipulated:

Louis P. Willemin, deputy public defender for Maryland's Howard and Carroll counties, said an incident of alleged lab misconduct is "the defense's worst nightmare because it's not the easiest thing to find out." "It's just a real significant problem when that happens because everybody is relying on [the analyst's] integrity," he said. "None of us are scientists."

Others are praising Cellmark for its quick action:

Peter J. Neufeld, co-founder of the Innocence Project at the Benjamin N. Cardozo School of Law at Yeshiva University, said Cellmark should be "applauded" because it dealt with Blair in a quick and comprehensive way. "There is no technology that is immune from any kind of misconduct; people will always find a way around existing controls and quality assurance," he said. The incident "does not undermine the whole GeneScan process at all."

Bottom line: A lot of defendants will be seeking retesting by an independent lab when the prosecution is relying on results by Cellmark--especially those which were tested by Blair.

More details are here.