What To Know About Biological Tests For Intoxication

If you've found yourself arrested for driving under the influence (DUI), it's likely that your arrest was the result of one or more biological tests. While physical exercises (field sobriety tests) are commonly used to screen drivers suspected of being under the influence, those results alone are not usually enough to gain a conviction. Along with field sobriety tests are breath tests or ones that require bodily fluids to measure levels of alcohol and intoxication. Read on to find out more about breathalyzer, urine tests, and blood tests for alcohol.

Measuring Blood Alcohol Concentrations (BAC) on the Breath

Breathalyzers come in two methods, A small, portable device is commonly used at the roadside stop for measuring BAC on the expelled breath of a suspect. In some cases, the results are confirmed later using a larger, more sophisticated device. BAC levels are tricky to measure with these devices but they are inexpensive, fast, and easy to use. Unfortunately for suspects, breathalyzer results are rife with inaccuracies because of:

  • Improper calibration.
  • Poorly trained law enforcement personnel.
  • Issues with the subject like the use of breath fresheners, mouthwashes, and toothache medication.

Measuring BAC With Urine

Though this way of measuring BAC is known to be extremely inaccurate, it is still used in some locations possibly because it's easy to administer and doesn't require medical personnel. The problem is that urine is highly sensitive to issues with temperature, collection methods, storage, and more. Your defense lawyer may be able to invalidate urine BAC tests based on these collection methods.

Measuring BAC Using Blood

This form of testing requires medical personnel to administer the blood draw and may require a warrant due to its invasive nature. However, if performed correctly, the results are extremely accurate. On the other hand, not all blood samples are properly handled. Your DUI lawyer will need to examine some fairly technical aspects of the way the blood was drawn, stored, transported, and more. False-positive results are possible with a sample that was allowed to coagulate, for instance.

When it comes to getting a conviction, the state has to have irrefutable proof that you were legally intoxicated. All of the above biological forms of proof are used in tandem with field sobriety tests, the officer's report, and camera footage of the roadside stop. Defendants need to know that no form of DUI proof is definitive. A criminal defense lawyer can examine the testing and create enough doubt for charges to be reduced or even dropped. Contact a criminal lawyer for more information.