Nearly three years after the Nassau County police crime lab was shut down because of testing errors there, prosecutors this week alerted several defense lawyers about a new mistake -- this time when a technician accidentally switched two DWI blood samples, NBC 4 New York has learned.
Maureen McCormick, who heads the Nassau DA’s Vehicular Crimes Bureau, told defense lawyers in a letter obtained by News 4 that an analyst at the Nassau lab "inadvertently switched the order of two blood samples" and said that the initial lab reports in the cases were switched as well.
McCormick said in the letter that the mistake appears to be isolated, but said her office wants to retest the blood in the other cases handled by the lab technician who made the mistake.
There are 31 such cases in all, a DA spokesman said Tuesday.
County officials closed the lab in 2011 after it was placed on probation because of concerns over the handling of evidence and other deficiencies. Nine months later, then-state Inspector General Ellen Biben issued a 170-page report criticizing officials for failing to act on signs that the lab was rife with problems.
Since then, the county medical examiner’s office has overseen testing of most evidence in criminal cases, replacing the 21 officers who worked there when the lab was run by the police department with civilian scientists.
Marc Gann, an attorney who was notified that two of his cases will be retested, said he was "shocked" that the new crime lab was reporting mistakes.
While he said he gives prosecutors credit for being forthcoming about the error, he said he also has unanswered questions.
"It causes me to question even more significantly the scientific testing that’s being done," Gann said.
The medical examiner's chief toxicologist told NBC 4 New York that the analyst responsible for the mixup is no longer testing blood.