Should I take a blood or breath test?

The number one question I get asked is whether to take a breath or blood test if you are suspected of DWI. The question highlights a fundamental right of all persons suspected of a criminal act: the right to not be compelled to incriminate oneself. Our Nation’s Founders thought enough of a citizen’s right against compelled self-incrimination to outlaw the practice in our Courts.

However, our Founders didn’t outlaw voluntary self-incrimination, so statements you volunteer to officers are generally admissible, and evidence you voluntarily produce is generally admissible against you. This is why the in-car video is such a great asset to both the prosecution and the defense. If you voluntarily take field sobriety tests, your voluntary performance will normally be shown to a judge or jury. If you voluntarily take a breath or blood test, your voluntarily produced evidence will normally be shown to a judge or jury. If you voluntarily call the arresting officer names in the patrol car, this will also normally be shown to a judge or jury.

Nobody can tell you what to do in your particular case, and I won’t attempt to do so. The answer attorneys give to the broad question of “whether to take a breath/blood test,” is generally no. Why? First, our Founders valued your right against self-incrimination so dearly they penciled it in to the United States and Constitution. Why should you surrender it so easily?

The more compelling reason, however, is that the science behind breath and blood testing is so complicated that it is extremely difficult to educate judges and juries (and oneself) on what a breath or blood test result actually means. We all absorbe and eliminate alcohol differently. The factors that contribute to whether you are above the .08 legal limit at the time of driving are numerous: body mass, gender, digestion, metabolism etc. Our “time to peak” – when bodily alcohol concentation is at its highest – varies greatly from person to person.

One of the world’s greatest experts on alcohol and the human body, Dr. Kurt Dubowski, found in a large sample of men and women that “time to peak” is between 14 and 138 minutes. So, there is much guesswork involved in how the breath or blood reading (normally taken between 30 minutes and 90 minutes after arrest), actually compares to your alcohol concentration at the time of driving. The likelihood that you could be under the limit while driving but over the limit when tested is legitimate.

There are other factors that can cause an increase in the breath machine result such as mouth alcohol, acetone (a natural digestive enzyme), breath temperature, breath volume, computer error, calibration error, and operator error. The question you (and only you) as an individual must ask and answer for yourself is whether you trust the result of such a test, and whether you believe such a test is in your best interest. I cannot advise you individually on whether a test is in your best interest, as only you are in the position with the information when you are driving or arrested.

Additionally, Texas law gives little incentive for a driver to take a chemical alcohol test. A conviction for first-time DWI carries with it an additional $1,000 a year (for 3 years) surcharge – whether or not you take a breath or blood test. If your breath or blood test is above a .15 concentration, you can face a $2,000 a year surcharge for the same period. On top of that, just an arrest for DWI carries with it a 90 day license suspension if you take a chemical test and fail, and a 180 day suspension if you refuse. However, you have a constitutional due process right to an adversarial, contested driver’s license hearing at which your attorney can save your driver’s license due to numerous reasons. Also, if your license is suspended, you normally have the right to apply for an occupational license in your county of residence or the county of arrest, in either District or County Court.

Finally, you can be prosecuted for DWI even if you blow under the legal .08 limit, and I have defended these cases before. The DWI statute outlaws driving without “normal use of your mental or physical faculties” by reason of introduction of alcohol (and/or drugs). Therefore, you can be prosecuted separately under this “loss of normal use” standard regardless.

This information is for your benefit, but obviously you are the one who will choose how much (if anything) to drink, and when you decide whether or not you are “good to go,” you should do your best to make sure that you truly are. Responsible social drinking isn’t a crime, so make sure that if you do drink that you are responsible about the choices you make, including the choice of whether or not to drive (or who to let drive you). A chemical test is not an automatic killer of your DWI case if you take/have taken one. There are many problems with the testing an many experts who can be retained to assist the jury in understanding the many problems and how they apply to your case.