A DUI is a serious charge that may have significant consequences for your future educational and career prospects. There are tests police officers may perform when they stop you.
Generally, the tests used are physical or chemical. However, these common tests have flaws that may lead to a false positive result.
The blood-alcohol concentration limit for a DUI in Minnesota is 0.8 (though you may find yourself arrested even if it is under this). A breath test analyzes your BAC based on your breath. However, it may read that you are over the limit even when you are not if you recently ate foods like fruit or protein bars or drank an energy drink. Extreme stomach acidity and conditions like acid reflux may also result in an inaccurate reading. Even the lingering effect of mouthwash, mints or cough medicine may cause one.
If you drank right before the police pulled you over, this may also cause the test to read your BAC as higher than it is; there needs to be a fifteen-minute interval between your last drink and the test for accuracy. The test itself does not have perfect accuracy, and police officers may perform improper calibration.
The field sobriety test actually consists of three tests that check your coordination. The problem is that it is subjective. The police officer has to use his or her judgment. You may also fail for other reasons, such as illness, exhaustion or nerves, which may all cause trembling or less-than-perfect coordination.
The tests used for DUI are not infallible. If you find yourself charged because of a false positive, you may still end up arrested, but you have a potential defense in court that may result in the tossing out of the case.