Top 11 Breath Test Defenses for a Michigan DUI Case

If you were arrested for DUI in Michigan, then you were likely given either a breath or blood test. The purpose of this test is to determine if you had a bodily alcohol level at or above Michigan’s legal limit of .08. Because a breath test above the legal limit is all the prosecutor needs to prove your guilt, a successful trial defense requires a successful breath test defense.

Many lawyers see DUI cases with breath tests as not defensible. While there is little question that juries tend to give breath test results a great deal of “weight” in deciding their verdicts, all breath test cases are defensible at trial. For example, the Michigan DUI lawyers at the Barone Defense Firm have successfully used all eleven of the following defenses:

  1. Breath Test Operator Mistakes – the typical DUI officer in Michigan has only attended a single one-day course after which they become certified class II operators of the breath test machine, in Michigan called the DataMaster DMT. Only a couple hours of this one-day training actually covers the administration of the breath test. The rest of the training relates to things like how the machine works, how to fill out paperwork and other related administrative tasks and functions. There is a written test given after the training, and officers only need to score a 70% to pass.  If they don’t pass a second time, they can retake the training, after which they get two more tries. Basically, this means everyone passes. Making matters worse, after this “training” there is almost no oversight in the field to confirm that the officer is properly administering the test, and the training does not include a practicum. Because the training is so inadequate, officers often make mistakes in administering the breath test, mistakes they may be totally unaware they are making. Some of these mistakes can lead to false and unreliable test results. These mistakes can be uncovered through a careful review of the breath test being administered and/or through cross-examination at trial.
  2. Abnormal Red Blood Levels – human blood is made up of several constituent parts, including red blood cells. The levels of a person’s red blood cells is called their hematocrit. Red blood cells are necessary to carry to alcohol a person has consumed from their gut to the brain and lungs. Consequently, if a person has an abnormal hematocrit level, meaning their hematocrit varies from average, then this abnormality can result in falsely reported breath test result because their breath has more alcohol in it than would an average person of same gender weight and body mass who has consumed the same number of drinks.
  3. Unusual Weather – yes, something as simple as the weather can change a reported breath test result. This is because barometric atmospheric pressure impacts what is called “partition ratio” meaning the partitioning of alcohol from blood to breath in the lungs. This is one reason barometric pressure can impact the reading of a dry gas simulator test causing the factors for same to be adjusted for breath testing devices located in high altitude locations. Things like gravity, temperature and density can all change barometric pressure, and as air moves around our planet, and therefore as barometric pressure changes, so does the weather. And, so do breath test results.
  4. Poor Breath Test Maintenance – We’ve already addressed how poorly breath test Class II operators are trained, and the same is true of Class III and IV operators. There is the additional problem of lack of oversight. Combined, these two problems, along with a few dishonest cops, all lead to the 2020 breath test scandal in Michigan. Maintenance issues can be uncovered through a careful review of the logs the police are required to keep as well as thorough cross-examination of the individuals charged with the maintenance of the machine.  Just like anything else, to be kept running properly and reporting reliable results, the breath test machines must be properly maintained.  Sometimes, they are not.
  5. Faulty Simulator Solutions – Michigan breath test machines are run through calibration checks once per calendar week using dry gas simulator solution.  The 120-day simulator tests are wet bath tests. Any variation in the manufacture or production of these simulator solutions can cause a DataMaster to have faulty calibration.  Because a breath test result is only as accurate as the simulator solution to which it is being compared, faulty simulator solutions can lead to faulty test results.
  6. Radio Frequency Interference – the DataMaster DMT is an electronic device the results of which can be impacted by radio frequency interference (RFI). Just as your Wi-Fi signal stops working when the microwave is on, the DataMaster breath testing device in Michigan is subject to reporting false results when certain other equipment is being operated nearby. This is one reason the old DataMaster’s had RFI antennas on them which would cause the device to shut down if RFI was detected.  The manufacturer claims that the “new” DMT is impervious to RFI, but no peer review studies have demonstrated that this claim is true. The DUI attorneys at the Barone Defense Firm have watched many video records of breath tests and it’s not unusual for officers to leave their prep radios on while in the booking room or even allow a cell phone to remain on or in use during a breath test.  Such mistakes can lead to false breath test results.
  7. Unusual Breathing Pattern – There are four breathing pattern related factors applicable to breath testing, two of which address total breath volume and rate of breath being delivered. There are multiple problems with the current breath test machine in Michigan, and inadequate monitoring of breathing pattern is one of them.  Peer review journal scientific studies have shown that a long breath can produce a higher test result than a short breath. This defense is closely related to partition ratio, which is why, according to Dr. A.W. Jones, one of the world’s leading scientists in this area, has indicated that something as simple as holding the breath for just 20 seconds can significantly increase a breath test results, biasing it as much as 15% too high. Closer to home, a Michigan scientist by the name of Dr. Dennis Simpson indicated that in some cases breathing pattern alone can cause a test result to be as much as .04 too high. If you blew near the legal limit of .08 this .04 alone can be the difference between guilty and not guilty.
  8. Body and Breath Temperature – one of the many assumptions the programmers of the DataMaster breath test machine made was that you had a 34 deg centigrade breath temperature when you blew into the machine. Because heat drives the alcohol from your breath into your lungs, if you had a fever when you blew into the machine, causing your breath to be higher than the assumed 34 deg centigrade, then there will be too much alcohol in your breath, and the reported result will be falsely high. This is why the temperature of the simulations discussed above is so important and the rules require that temperature be measured.
  9. Mouth Alcohol – of the four sample acceptance or breath pattern parameters discussed above, two of them address mouth alcohol. The idea is that if mouth alcohol is present, it will be detected and flagged by the machine.  Trouble is, mouth alcohol detectors don’t work, and if mouth alcohol is present and the machine misses it, the result will be grossly elevated.  This is because only a small amount of mouth alcohol causes a disproportionately high test result. Heart burn or GERD is the most common cause of mouth alcohol and if you suffer from this health issue, then the only reliable way to test your bodily alcohol level is with a blood tests.
  10. Arterial vs. Vein Blood Differences – if a legal limit means anything then there should be no difference in the test used to determine your alcohol level.  In Michigan, the officer can choose the test and it can be breath blood or urine. Trouble is, breath testing relies on arterial blood whereas blood testing relies on vein blood. The reason this is a problem is that the only time breath and blood alcohol levels are the same is when a person has reached an equilibrium between alcohol left to be absorbed from the gut and alcohol already present in the blood.  In other words when there is an equilibrium between the alcohol being absorbed and burned.  For most people, this equilibrium occurs at 45-60 minutes after the last drink.  But it can take way longer than this, and if you are still absorbing, then a breath test can be as much as 230% too high when compared with a simultaneous blood test.
  11. Diabetes and Chemical Interference – Breath testing machines in Michigan use the science of infrared spectroscopy to measure the amount of alcohol in a breath sample. By way of a simplified explanation, an infrared light of a known intensity is passed through the sample chamber inside the breath test machine that has captured a volume of the driver’s breath. The intensity of the light is measured and any decrease in intensity is attributed to the amount of breath alcohol present in the sample. A really drunk person will have a lot of alcohol in the breath and the decrease in the light intensity will be much greater than a person who has had nothing or very little to drink. Trouble is, the machine only measures infrared absorption in a given bandwidth, in this case 3.4 microns. Because other molecules that can be present in a person’s breath such as acetone also absorb infrared at 3.4 microns, if they are also present the breath test machine can misread them as beverage alcohol causing a false high result.  Diabetics for example can have acetone on/in their breath, and if the “filter” used to distinguish beverage alcohol from acetone fails to catch this, an innocent person can go to jail.

These eleven defenses only scratch the surface of all the available defenses to a breath test.  If you were arrested in Michigan and your breath tested above the legal limit, call the Barone Defense Firm and have one of the experienced DUI lawyers review your case.  The evaluation is free, and it could make a big difference in the outcome of your case.

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