Although blood tests are thought to be more accurate than some other types, the reality is that a DUI blood test may come back with a false positive that leads to confirmed charges and a potential conviction. Even if you were not impaired at the time of a traffic stop, delays in testing and errors in testing may result in false positives.
Inaccuracies could have a long-term negative impact on your life, so it’s essential to take steps to resolve them. Here is what you should know about how blood tests can go wrong.
Storage and protection against contamination matters
One of the first things to consider is that storage problems can cause issues with accuracy. For example, if the sample is contaminated, even blood with no alcohol concentration may ferment due to bacterial exposure and read as containing alcohol.
The mixture must be accurate
Every test tube contains sodium fluoride and potassium oxalate. When those chemicals are not included in the right ratios, there is a risk that the blood could congeal or have a false positive reading. If the blood coagulates during the testing process, new blood should be drawn. If the test comes back significantly different from the Breathalyzer test, then it’s necessary to look deeper into the results.
Timing is important in DUI cases
Getting the timing right is also important in DUI cases. This is because someone may be driving and feel fine at the time of a stop but read as impaired if enough time has passed. How? If you drink, the alcohol won’t absorb into your blood right away. It could take 30 minutes, 45 minutes, an hour or longer to feel the full effects of alcohol.
That means that a test taken at 10 p.m. might read differently at 10:45 p.m. The issue there is that your arrest was at the earlier time so the new reading may be higher than your BAC actually was at the time of the traffic stop.
These are three reasons that a blood test may not be accurate in a DUI case. Consider these to help protect yourself if you’re accused.