PinIn a surprising admission out of Pennsylvania, a local district attorney was forced to reveal that medical personnel and prosecutors had been incorrectly testing the blood of suspected drunk drivers. The issue was not merely a procedural problem, but a crucial mathematical mistake that led to wildly inaccurate readings and possibly even mistaken convictions.

The news came out of Somerset County, where District Attorney Lisa Lazzari-Strasider noted that the mistake was made when the local hospital, where suspects were taken to have their blood drawn, chose to test a driver’s blood serum, as opposed to the entire blood sample. Though this can be perfectly acceptable and result in accurate readings, it only works if a second step is taken, with others performing a calculation to convert the BAC sample found in blood serum to the proper level for the entire blood sample. Without the conversion, the amount of alcohol in a driver’s blood is overestimated, by as much as 15 percent.

According to court procedures common in Pennsylvania, blood serum tests can be admitted into evidence and used as proof that a driver was impaired. However, the test must first be converted into a whole blood sample number. The district attorney admitted that this is where the mistake happened, with prosecutors in her office failing to perform the necessary calculations.

So far, the DA says only that her office will begin reviewing some recent cases and convictions to see if the mistake impacted any defendants. Criminal defense attorneys in the area are already chomping at the bit for more information about the error and for how long the conversion mistake had been taking place.

Though 15 percent overestimation of a person’s BAC may not seem too bad, the reality is that anyone on or near the line could have been wrongly convicted as a result of a 15 percent mistake. Not only could sober drivers have been charged with DUI, but drivers who were genuinely impaired may have been given additional charges or aggravated sentencing due to the inaccurate tests.

For blood tests to be used in court, often as decisive evidence against a defendant, they must be credible and routinely reliable. This case illustrates the doubts that exist about the accuracy of some sampling and how something as simple as careless human error could jeopardize the freedom of potentially thousands of innocent drivers.

Source: “Oops: County wrongly figured blood-alcohol levels,” published at MSN.com.