How to Challenge Breathalyzer Accuracy in a DUI Case

Breathalyzer accuracy plays a crucial role in determining the outcome of DUI cases, as inaccurate results can lead to wrongful convictions. If you are facing DUI charges based on breathalyzer results, you should understand factors that can affect breathalyzer accuracy, how they can be challenged, and other key information that is important to your defense.

Challenging the accuracy of these tests can be an effective defense strategy in court, helping to weaken the prosecution’s evidence. With a strong defense, a DUI attorney works to reduce or dismiss the charges.

How Reliable Is a Breathalyzer Test?

One of the first questions that arise after someone is arrested for DUI is, “How reliable is a breathalyzer test?”

Breathalyzer tests are not always reliable, which could be due to factors like:

• Improper maintenance – Like any device or machine, breathalyzers require routine maintenance. 
• Calibration errors—Breathalyzer accuracy is dependent on regular calibration. If this is not completed, errors will ultimately occur.
• Operator mistakes – If the officer does not accurately administer the test, such as not instructing you properly how and when to blow into the breathalyzer, their mistakes can influence reliability.

These issues can lead to faulty readings. A DUI attorney will scrutinize any issues that affect reliability during a DUI defense.

How Accurate Is a Breathalyzer Test?

Multiple factors can compromise breathalyzer accuracy. Any of these factors could be used in your defense. These include:

• Medical conditions – if you have a condition such as gastroesophageal reflux disease (GERD) or other gastronomic disorders, hypoglycemia, or increased ketones due to high-fat and/or high-protein diet.
• Residual mouth alcohol – dental work/adhesives can trap alcohol. Also, medications such as mouthwash, Nyquil, Vicks products, and even breath sprays can contain alcohol.
• External environmental influences – if you work in a profession exposed to high levels of acetone (nail technician/painter), chemicals in the area, or other environmental influences.

How accurate is a breathalyzer test? It depends on whether it has been compromised.

The factors listed above can result in false readings, making the results questionable in court.

Common Excuses for Failing a Breathalyzer Test

Defendants in many DUI cases cite common excuses for failing breathalyzer tests. 

Foods

One excuse is that the defendant had a specific food before the test. This could include ripe fruits, fermented food or soda, energy drinks, hot sauce, protein bars, or baked goods that contain a high level of yeast. These kinds of foods and beverages can “mimic” alcohol. 

Medications

Medications, as listed above, are another common excuse. Other medications cited may include Anbesol (used for canker sores and toothaches), asthma medications such as Albuterol (if used right before the test), and certain over-the-counter cold medicines. 

Test Mishandled

If an officer mishandles the test, a defendant may also cite this. Breathalyzer accuracy can be affected by how the test is administered. If they instruct you properly or do not interpret the results correctly, this could be an excuse for failing a breathalyzer test.

These excuses can sometimes serve as legitimate defenses when thoroughly investigated.

Legal Defenses Based on Breathalyzer Accuracy

Breathalyzer accuracy is the foundation of many legal defenses in DUI cases. 

To determine the best strategy for your case, your attorney will investigate the breathalyzer test's arrest and administration. Here are common legal defenses attorneys use to challenge the breathalyzer’s accuracy:

• Questioning the breathalyzer’s calibration - can produce erroneous results without proper calibration. The attorney would work to prove that the calibration of the breathalyzer was not as it should be, affecting the test results.
• Questioning the administration of the test: police officers are not scientists and can make mistakes when testing someone with a scientific device. This could be a valid defense if the attorneys find that mistakes were made.
• Questioning the presence of external factors - various situations can affect breathalyzer accuracy. If external factors were present that could alter the test results, your charges may be reduced or dismissed.

Defense attorneys may also use the rising BAC defense. The rising BAC (Blood Alcohol Concentration) defense utilizes the fact of how alcohol metabolizes in your body. When someone is drinking alcohol, it takes time for it to metabolize fully. Your BAC will continue to rise over time. 

Your attorney may argue that your BAC was not above the legal limit at the time you were driving, even if it was above the limit at the time you actually performed the breath test.

How to Prove Breathalyzer Test Inaccuracy in Court

Raising the question of breathalyzer accuracy is a valid strategy for many DUI cases, but there needs to be a plan to prove breathalyzer test inaccuracy in court. There are multiple options. The chosen strategy will depend on the particular case. 

Expert testimony may be utilized to prove breathalyzer inaccuracy. These experts typically have extensive experience in forensic analysis and breathalyzer technology. During their testimony, they can provide insights and analysis into the validity of the procedures during the test, the accuracy of the device, and possible issues related to maintenance and calibration. 

Another tactic attorneys use is closely analyzing maintenance records of the device used in the breathalyzer test. All devices that give breathalyzer tests must have regular maintenance and calibration, with associated documentation of such activities. If records are incomplete, this may prove the test results are inaccurate in a DUI case.

Since breathalyzers are scientific devices, scientific studies have been published on them. These studies discuss how they work, their qualities, new technology, and potential vulnerabilities. Attorneys can also reference certain scientific studies on the limitations of breathalyzers in court. 

These strategies help create doubt about the validity of the test results.

Factors That Can Affect Breathalyzer Accuracy

How do various factors affect breathalyzer accuracy? Let’s discuss.

Medical Conditions

A medical condition like GERD can create falsely elevated BAC levels due to stomach acids and gases that flow back into the esophagus and mouth, which may contain alcohol from recent consumption. If you have diabetes, the waste substances your liver produces (ketones) can alter results. Medications can also affect breathalyzer accuracy. 

Chemical Exposure

Chemical exposure in the area, such as from paint, acetone, and adhesives, can distort breathalyzer results. Are factories or warehouses in the area where you were pulled over? What is in your sample when you take the test may be detected as alcohol by the device.

Malfunctions

Machine malfunctions or improper use also contribute to inaccurate readings. The sensors may fail, the samples may not have been obtained correctly, or the test timing may be incorrect. If a test is given less than twenty minutes after an individual eats or drinks something, puts a foreign object in their mouth (like a cigarette or breath spray), or belches/vomits, this can also affect breathalyzer accuracy. Additionally, if an officer or staff member in the breath testing facility uses an electronic device too close to the instrument, that will interfere with the results.

How to Challenge a Breathalyzer Test in Court

Challenging a breathalyzer test in court should be conducted strategically.

It starts with gathering evidence on how the test was conducted, reviewing the officer’s actions, and questioning the device’s accuracy. Some questions (and their follow-up explanations) that can create doubt about the validity of the test results include:

• Were the samples collected appropriately? 
• Were there problems with the timing of the test? 
• Was the officer using the device properly? 
• What factors are present that could alter breathalyzer accuracy?

The defense attorney can also challenge breathalyzer accuracy in court by presenting alternate explanations for high BAC levels, such as medical conditions or chemical exposure. This strengthens the defense.

Excuses for Failing a Breathalyzer That May Work

The defense for failing a breathalyzer test will differ on a case-by-case basis. However, some excuses for failing may work in a DUI case involving breathalyzers. 

Defenses such as device malfunction, interference from medical conditions, or improper handling by officers may successfully challenge breathalyzer results. Sensors or other components may fail on the device. The physical condition of your body at the time of the arrest can alter results. An officer may make a mistake during the administration of the test. These situations may occur when someone is pulled over for suspected driving under the influence.

And these reasons can introduce reasonable doubt in DUI cases.

Seek Legal Counsel for DUI Cases Involving Breathalyzer Tests

If you are facing DUI charges based on breathalyzer results, seeking professional legal help is critical. Do not attempt to handle a DUI case on your own.

Florida DUI laws call for harsh penalties for people who are convicted of driving under the influence. A skilled DUI attorney can challenge the breathalyzer's accuracy and work toward reducing or dismissing the charges. 

The Denson Firm has the experience you need to represent your case and protect your rights aggressively. Contact us today for a free, confidential consultation.