A recent letter from the Forensic Science Department of the Michigan State Police revealed that there are apparently thousands of drunk driving cases whose results are tainted. The reason for the problem according to the letter, is that the samples were processed in part using a machine that was incorrectly calibrated.

The error was discovered in April of 2016, during a routine case review. The Michigan State Police say they took immediate action in dealing with the problem. Lab equipment was carefully recalibrated, and all of the cases that could have been affected were retested. The results, while illuminating, were not as drastic as many recently convicted drunk drivers would have hoped for.

According to the letter, which was signed by Acting Commander of the MSP Forensic Science Division, L. Scott Marier, those results that were incorrect were off by a range of  -0.002 g/dL to +0.004 g/dL. G/dL means grams per deciliter, which is how medical tests results are reported. However, as it says in the letter, “none of the cases originally reported near Michigan’s legal blood alcohol limit of 0.080 g/dL have amended results which move them across the threshold in either direction.”

This means that, while there were a substantial number of case results that were incorrect, they weren’t incorrect enough to have had any bearing on the outcome of the case in court. The only instances where the correct results differed enough to make a difference in the charges was with regard to eighteen super drunk driving cases.

According to the letter, the eighteen ‘super drunk’ cases in question were actually initially in favor of the defendant. With the retesting, the results now reveal that the defendant was actually above the ‘super drunk’ limit, where before they were thought to be below it.

Once the cases were all re-tested, and correct results determined, amended reports were issued to all of the agencies and prosecutors that may have been affected. In essence, any cases where a change in result occurred, a letter was sent out containing an explanation of what had happened and what the new, accurate result was.

All in all, a total of 2,007 case results were determined to be incorrect, out of the 4,001 cases that were tested during that window of time. Given the number of cases where the results were in question, a number of people have gone on the record to question the credibility of the MSP Crime Lab. In the light of the scandal earlier this year surrounding allegations of falsified marijuana toxicology results, this hasn’t been a very good year for the Michigan State Police crime lab.