Exhale! Blow, blow, blow! Get it all out, keep blowing, yell the Cops!

Remember, I was a cop for almost 3 years in Williamson County, Texas.  And, while I never sought out the training to administer the breath tests on any of the machines that allegedly measure alcohol concentration on a person’s breath, I definitely was present when these tests were given by cops, and most of the time, I felt like I had somehow slipped into a boot camp and that there was a drill sergeant present to coach the person into giving a deep lung sample.  In fact, the training manuals actually call the samples "deep lung air" and teach officers to get suspects to blow, blow, blow, keep blowing until they have pushed all the air out of their lungs.  When blowing this much air out, it almost feels like you are going to throw up, especially if you have any lung ailments or breathing difficulties.

While I’m glad to see that we are pushing forward and not afraid to take a case to trial only because of a number on a breath test, the sad fact is that many agencies are beginning to seek blood more and more and that many state legislatures are allowing it too! Fortunately, juries still have the ability to watch the video and see the person’s performance and not convict solely based on a number on a piece of paper.

As always, I believe a person should refuse to do all the field sobriety tests and yes, there’s a strong likelihood of being arrested, but the statement by the officer, "I just want to make sure you are okay to drive" could not be further from the truth.  Please, minimize the evidence cops gather against you by remaining silent and refusing these ridiculous tests.  My only exception to refuse breath tests is to avoid blood being taken…. it is far better to only share that sample than the contents of everything tracked in our blood….

Lawrence Taylor posted on his DUI blog following article about a month ago and I must say that I agree with the findings written in it along with the mentality of the training and officers that administer the breath tests:

Breathalyzer Results Depend Upon Your Breathing Pattern

Want to trick that breathalyzer into a false reading? Not that difficult: just change your breathing pattern.

As I’ve indicated in literally hundreds of earlier posts, these breath machines which determine guilt or innocence in DUI cases are not exactly the reliable devices that law enforcement would have us believe. (See, for example, How Breathalyzers Work – and Why They Don’tWhy Breathalyzers Don’t Measure Alcohol and How Accurate Are Breathalyzers?.)  Yet another example of that unreliability is the fact that the results will vary depending upon the breathing pattern of the person being tested.

This has been confirmed in a number of scientific studies.

In one, for example, a group of men drank moderate doses of alcohol and their blood-alcohol levels were then measured by gas chromatographic analysis of their breath. The breathing techniques were then varied.The results indicated that holding your breath for 30 seconds before exhaling increased the blood-alcohol concentration (BAC) by 15.7%. Hyperventilating for 20 seconds immediately before the analyses of breath, on the other hand, decreased the blood-alcohol level by 10.6%. Keeping the mouth closed for five minutes and using shallow nasal breathing resulted in increasing the BAC by 7.3%, and testing after a slow, 20-second exhalation increased levels by 2%. "How Breathing Techniques Can Influence the Results of Breath-Alcohol Analyses", 22(4) Medical Science and the Law275.For another study with similar findings, see "Accurate Measurement of Blood Alcohol Concentration with Isothermal Breathing", 51(1) Journal of Studies on Alcohol 6.

Dr. Michael Hlastala, Professor of Physiology, Biophysics and Medicine at the University of Washington has gone farther and concluded:

"By far, the most overlooked error in breath testing for alcohol is the pattern of breathing….The concentration of alcohol changes considerably during the breath…The first part of the breath, after discarding the dead space, has an alcohol concentration much lower than the equivalent BAC. Whereas, the last part of the breath has an alcohol concentration that is much higher than the equivalent BAC. The last part of the breath can be over 50% above the alcohol level….Thus, a breath tester reading of 0.14% taken from the last part of the breath may indicate that the blood level is only 0.09%." 9(6) The Champion 16 (1985).

Many police officers know this. They also know that if the machine contradicts their judgement that the person they arrested is intoxicated, they won’t look good. So when they tell the suspect to blow into the machine’s mouthpiece, they’ll yell at him, "Keep breathing! Breathe harder! Harder!" As Professor Hlastala has found, this ensures that the breath captured by the machine will be from the bottom of the lungs, near the alveolar sacs, which will be richest in alcohol. With the higher alcohol concentration, the machine will give a higher — but inaccurate — reading.