When someone is arrested for driving under the influence, police may request that they provide a blood sample to determine blood alcohol concentration. Generally, these blood tests are considered to be more reliable than tests using a Breathalyzer. Questions have arisen, however, regarding the accuracy of blood alcohol tests performed at the Wisconsin State Laboratory of Hygiene.
Labs generally use a technique called gas chromatography to determine the amount of alcohol present in a blood sample. This process is particularly well suited to separating and measuring the concentration of certain organic compounds in blood, including alcohol and the metabolites produced after a person ingests certain drugs. The basic idea is to vaporize the sample and to determine whether certain compounds are present. The results are displayed on a graph called a chromatogram.
If a test is conducted properly, the chromatogram will consist of a flat line interrupted periodically by peaks. Each peak represents the presences of certain substances in the sample. Ideally, each peak is discrete: that is, the separation between each peak on the graph is such that it is easy to determine which substance is which.
Recently, some chromatograms produced by the Wisconsin State Laboratory of Hygiene show a series of jagged peaks on the left side of the graph. It is unclear what is causing these peaks, but both the lab and Perkin Elmer - the company that manufactured the gas chromatograph equipment - acknowledge that they should not be there. The fear is that the equipment is malfunctioning.
Despite the hygiene lab's acknowledgement that some chromatograms have exhibited abnormalities, it continues to stand by the reliability of its results. It has noted that control tests performed with this equipment have all been well within manufacturer specifications. The fact is, however, that neither the lab nor the manufacturer can explain what is causing these potential malfunctions. Even if the control tests have been found to be accurate, that is not necessarily an indication that results exhibiting these mystery peaks are also accurate. Without identifying the definitive cause of these issues, it is difficult to say with certainty that chromatograms produced at the lab are reliable.
For those who are facing DUI charges, it is imperative to speak to an attorney with experience defending those accursed of these sorts of crimes. A DUI attorney knows how the system works and can help you take steps to protect your rights. To learn more, schedule a consultation with a DUI attorney today.