Though this did not occur in Virginia, one state's experience demonstrates problems that can arise when it comes to DUI cases. Possible problems in the manner in which blood samples were tested resulted in questions about the validity of these tests in thousands of cases.
Lab officials have claimed that unexplained peaks on certain graphs did not mean that the reliability of 17,000 other tests in the same lab should be questioned. Yet one attorney suggested that a "jagged hump" appearing on chromatograms of certain blood tests may have indicated a possible malfunction by the measuring instrument. He did not feel such an anomaly could be ignored.
The chromatograms are used to separate out substances contained in the blood such as ethanol. While acknowledging that the humps should not be there, neither the instrument manufacturer nor the lab has been able to explain why the humps are appearing. At least one case has been challenged by demanding disclosure of this information.
Whether the defense lawyers will ultimately prevail in having a number of DUI convictions overturned based on the unexplained humps is still yet to be seen. There are still a number of individuals in the lab that defend the results that have been produced and insist that checks such as daily instrument calibration or double testing of certain samples are made to ensure errors do not occur.
No matter where such cases take place, DUI matters can be complex and can result in harsh penalties for those convicted. If arrested for DUI or other drinking-related offenses, it's important to speak to attorneys who are knowledgeable concerning the many aspects of DUI law and can represent you if such matters proceed to trial.
Source: Journal Sentinel, "Defense lawyers question results of blood-alcohol tests," Bruce Vielmetti, Feb. 16, 2014