Intoxicated driving in the state of Texas can result in misdemeanor charges. In a DWI case, one of the biggest and most common forms of evidence is chemical testing that shows blood alcohol concentration.
But of course, no test is infallible. It is important to understand the potential pitfalls of a DWI test.
How do BAC tests work?
Texas transportation laws highlight implied consent given by all drivers. This is the implied consent of all drivers when using public roads to take BAC tests.
First: how do chemical tests even work? The biggest test will use the breath of the driver in order to determine BAC levels. But if the police officer expects the use of drugs, they may also order a blood or urine sample instead.
In order to make a determination on these scales, officers will need roughly 210 liters of breath, 100 milliliters for blood or 67 milliliters of urine. This allows for the most accurate testing possible.
Problems with chemical tests
Of course, problems still exist even then. This is especially true of breath tests, which are common due to their low invasiveness.
For example, manipulation of the test or the use of an unclean device could sway the numbers. Improper calibration or error on the part of the machine or operator may lead to false reads, too.
On top of that, issues can happen in the laboratory, too. Samples may end up confused. Contamination from certain medicines may also change the individual’s breath, blood or urine that might trigger a false positive.
Understanding this is important when figuring out how to approach a potential DWI charge.