The problem-plagued crime lab in Nassau County was abruptly shuttered Friday after authorities uncovered a series of drug-testing mistakes.

The lab was the only crime lab in the country that was on probation, a designation it earned when a national accrediting group reported last December that it didn't maintain equipment, store evidence or keep records properly. It was the second time in three years the lab got slapped with probation.

District Attorney Kathleen Rice said she was never told the lab -- which was run by county police -- was ever put on probation until the board released its report last December. 

She requested that the county shut down the lab after her office found inaccuracies in the way the lab tested for the drugs ecstasy and Ketamine. County officials said the mistakes were confined to only drug tests, but they closed down the entire lab -- which also analyzes ballistics, blood, fingerprint and other crime evidence -- as a precautionary measure. 

So far, they say there's been no evidence of intentional wrongdoing.

Rice said it's possible some convictions might have to be overturned, and her office is now reviewing about 9,000 drug cases between 2007 and 2010 to decide how many drug tests should be redone. Defense lawyers, meanwhile, will be referring to the office any past cases they think deserve review. 

Rice has said she is willing to consider modifying any past pleas or convictions based on erroneous drug tests.

Nassau County Bar Association president and longtime defense lawyer Marc Gann said a number of clients have already asked him to request review of their convictions. Gann said most of the mistakes by the lab appear so far to affect only the amount of a drug found on a defendant. Quantity measurements are important, Gann said, because they determine whether a defendant should be charged with a misdemeanor or felony.

"But there may also be concerns about the quality of the drug, as to whether or not the drug that was allegedly recovered was in fact that drug," he said.

For now, the county will be sending drug, ballistics, fingerprints and other crime evidence to outside contractors for analysis.  Gann said he doesn't think the outsourcing of crime evidence analysis will necessarily slow down criminal cases, but he does believe the District Attorney's review of thousands of old cases will be a problem.

"What I do think is a concern is that we don't know the volume of cases that may have been affected by what's taken place, and so the work that comes out of that may bog the system down," Gann said.

County officials said a state-of-the-art crime lab will be opened soon -- and it will be run by the Medical Examiner.