For as long as breathalyzer test results have been convincing juries that defendants were impaired behind the wheel, defense attorneys have been studying the accuracy of these results to prevent innocent people from false convictions. Breath tests, like those conducted on the Intoxilyzer 8000 — Florida’s only breath test machine approved for evidentiary use — were designed to measure a person’s breath alcohol concentration or BAC. If a person’s BAC is 0.08 or higher, it’s an indication that the person is legally drunk.
Once a jury finds out that the suspect on trial had tested at 0.08 or higher, they often conclude that the suspect is guilty of DUI. After the test result is introduced, juries often assume the case is over and expect the defense to prove why the defendant isn’t guilty, rather than assuming innocence until a finding of guilt. This is the main reason why defense attorneys often fight to challenge the results of BAC tests or how they were administered and try to prevent them from being used as evidence. The average juror fails to understand the many ways that a sober driver could produce a 0.08 or higher BAC.
What Could Go Wrong with a DUI Breath Test?
There are so many variables that affect the results that breath tests produce. Readings are often found to be incorrect. Many factors can cause breath tests to produce results that are erroneous or completely unrealistic, including false positives that could lead to a DUI suspect’s arrest. Some of the factors researchers have noted that can create a misleading BAC test result are:
Faulty Calibration
Breath test machines respond to temperature and provide inaccurate readings if they’re not calibrated to adjust to a change in ambient temperature. Unfortunately, researchers have found that, in police departments across the country, machines aren’t maintained properly, which includes calibration.
Improper Maintenance of Breath Test Machines
A report by the New York Times found that many police departments have poor maintenance standards and lack the expertise needed to perform proper upkeep of breath test machines. They even discovered that some departments use homemade chemical solutions — which often produce higher results — to operate the machines. In extreme cases, researchers found that machines produced BAC readings that were as much as 40% too high.
Breathing Patterns
Holding your breath for 30 seconds could result in an increased BAC. A BAC of 0.07 could jump to 0.81 or higher. Hyperventilation could free alcohol molecules in the trachea, reflecting a higher and inaccurate BAC.
Mouth Alcohol
Mouth alcohol is one of the most common reasons for an inaccurate breath test result. Mouth alcohol contaminates what would otherwise be a valid test. Testing standards require police to wait 20 minutes to avoid the presence of mouth alcohol; however, any alcohol that gets trapped in the mouth or airways can produce a false high read, and it could take more than 20 minutes to get rid of it. Mouth alcohol can come from mouthwash, cough medicine, chewing gum, breath mints, dental work, and health conditions like acid reflux.
Test Taken During the Absorptive Phase
When your body is in the absorptive phase, it means that alcohol is still entering your bloodstream. Your BAC is still rising. Tests taken during this phase could produce unrealistically high results that can hurt your case.
Acid Reflux and Other Medical Conditions
Acid reflux occurs when stomach acid or bile flows into the food pipe and irritates the lining of the esophagus. Symptoms typically include burning pain in the chest after eating and may worsen when lying down. The stomach acid introduces mouth alcohol, rendering the results of the test invalid.
Diabetes is another condition that can skew breath test results. A person with diabetes can have an acetone level that is hundreds of times higher than in a non-diabetic. Breath test machines interpret acetone as ethanol (alcohol).
Faulty Machines and Source Code
Even machines that have been properly calibrated may be faulty due to a problem that occurred during production. In Washington State, faulty programming in their breathalyzers caused the machines to produce inaccurate results. The court allowed defense lawyers to review the machine’s software. As they began to uncover the numerous errors with the machine’s source code, the manufacturer sent them a cease-and-desist order and forbade them from sharing their findings. The results were never made public.
In Florida, the Intoxilyzer 8000 performed about as well as Washington’s Alcotest 9510 when examined by toxicology experts. Yet, police departments throughout the state continue relying on the flawed technology, even when a court issued this statement in 2014:
“The Intoxilyzer 8000 is a magic black box assisting the prosecution in convicting citizens of DUI. A defendant is required to blow into the box. The defense has shown significant and continued anomalies in the operation of the Intoxilyzer 8000’s operation. The prosecution argues most of the tests do not show anomalies. In fact, a higher percentage of the tests may show no anomalous operation. That the Intoxilyzer 8000 mostly works is an insufficient response when a citizen’s liberty is at risk.”
What Could Go Right in a DUI Case?
If you’ve recently been arrested in Florida for drunk driving, you likely tested on an Intoxilyzer 8000 if you submitted to taking a breath test. Working with a DUI defense lawyer in West Palm Beach like Brian Gabriel, who has served criminally accused persons for more than 30 years, can bring fairness back into your case. Call The Law Office of Gabriel & Gabriel at (561) 622-5575 for a free consultation with Brian or complete a contact form.