Can You Still Be Charged With a DUI If You Pass the Breathalyzer?

If you are pulled over on suspicion of drunk driving, the results of a Breathalyzer test are just one form of evidence that officers can use. They may find enough reason to arrest you for driving under the influence (DUI).

Passing the test does not guarantee that you won’t get charged with DUI. In fact, many drivers are surprised to learn that a passing Breathalyzer result doesn’t automatically clear them of DUI charges. Similarly, failing a breath analysis test doesn’t guarantee a DUI charge will result in a conviction.

This article discusses the role blood alcohol content (BAC) tests play in a DUI case, particularly the Breathalyzer test. If you’re facing DUI charges, consider speaking with a DUI defense attorney about your case. They can examine the state’s evidence against you and help you build the best defense possible.

Why You Can Still Face DUI Charges After Passing a Breathalyzer

Even with a BAC reading below 0.08%, prosecutors can still pursue DUI charges if they believe you were driving under the influence. This is because DUI laws typically include two distinct offenses:

• “Per se” DUI, which occurs when you have a BAC of 0.08% (in almost every state) or higher
• Impairment DUI, which happens when you are under the influence of alcohol or a controlled substance, regardless of BAC level

A passing Breathalyzer test only protects you from the per se charge. However, it does not protect you from getting DUI charges based on impairment.

Evidence That Can Lead to DUI Charges

When you pass a Breathalyzer test, law enforcement doesn’t simply let you go. Instead, they will rely on other forms of evidence surrounding the case. According to the National Highway Traffic Safety Administration, there are 20 identifiable symptoms that may indicate a person is driving impaired. These driving patterns give police probable cause to stop a vehicle and investigate for driving under the influence (DUI).

Sworn testimony from an arresting officer and video footage of your motor vehicle before the stop may not be compelling evidence on their own. However, those pieces of evidence may also serve as the basis for a case even when breathalyzer test results are favorable to the defendant.

Statements from the driver are also admissible evidence. The police report could also include statements you’ve made. For instance, if you’ve admitted to having any number of drinks, you will see it in the police report. The state could use that evidence to support your DUI charges. Also, if you’re argumentative or hostile with the officer during your traffic stop, your demeanor could weigh against you in court if the state files charges.

BAC Testing and Implied Consent

If you’re asked to submit to a BAC test as a driver, you’re required to comply under state implied consent laws. By driving on public roads, you implicitly consent to chemical testing to determine impairment.

Suppose you refuse to submit to any chemical test, whether it’s a breath test, blood test, or urinalysis. In some states, the court could admit your refusal as evidence of guilt. However, in other states, prosecutors are not allowed to use your refusal as evidence against you.

In most states, your refusal will also typically result in an automatic suspension of your driving privileges.

Meanwhile, failing a chemical test with a BAC of 0.08% or higher puts you in the “per se” impairment category. Some state laws even allow drivers with BAC levels between 0.05% and 0.07% to be charged with a DUI offense if other evidence shows impairment.

How Breathalyzers Work (and Sometimes Fail)

A Breathalyzer (the brand name of an early breath-testing device) measures alcohol vapor in your breath. This device is the most commonly used chemical test for DUI suspects. However, the equipment has several drawbacks. The results aren’t generally enough to convict you without other evidence supporting intoxication.

A Breathalyzer measures an entire volume of air from your lungs. As a result, the test is susceptible to falsely elevated measurements from any alcohol trapped in your mouth or esophagus. There are also many factors that could affect the breath test result.

For instance, dental work, such as bridges or caps, could retain alcohol. Alcohol may remain in the esophagus after vomiting or due to any gastric reflux disorder. Mouthwash, breath mints, and other products may also contain alcohol and cause an erroneous BAC reading.

Alcohol isn’t instantaneously absorbed into the blood. That means BAC results can sometimes be refuted with a “rising BAC” defense. A test that’s delayed up to an hour after the initial stop may indicate intoxication. That’s true even though the alcohol had not been sufficiently absorbed to cause impairment at the time of driving.

This argument works both ways, depending on the delay between the driver’s last drink and the administration of the test. This is because an impaired driver can sober up while waiting to take the test. In any case, there must be proof of intoxication while actually driving.

Why Field Sobriety Tests Matter

After a passing Breathalyzer test, field sobriety tests become even more critical to the prosecution’s case. Law enforcement officers may administer a variety of field sobriety tests (FSTs) if they pull you over on suspicion of driving under the influence of alcohol or another substance.

Officers often rely more on these subjective tests when breath test results don’t support their suspicions of impairment. Police often record these tests on video. They help the state build a more solid case if you are charged. This supporting evidence may be used to counter claims that a breath test was inaccurate due to improperly calibrated equipment.

Field sobriety tests aim to highlight obvious physiological or mental impairment. They can be misleading, though. Police officers are trained to catch certain physical cues, but they aren’t medical professionals.

For example, the horizontal gaze nystagmus test — which requires you to follow a pencil, finger, or penlight visually — can be impacted by certain medications or medical conditions. An officer can’t reasonably determine what’s causing the nystagmus at the scene. Yet this sort of evidence may lead to a conviction despite a passing BAC test result.

Depending on the jurisdiction, you may have the right to request an independent blood test. Blood tests provide the most reliable measurement of BAC. Results may be used to defend against Breathalyzer results that might otherwise lead to a DUI conviction.

Get Legal Help if You Face a DUI After Passing a Breathalyzer Test

If you’re facing DUI charges despite passing a Breathalyzer test, don’t assume the case against you is weak. Breathalyzer tests, field sobriety tests, and questions about being over the legal limit can feel overwhelming. The prosecution may still have a viable case based on officer observations, field sobriety test results, and other evidence of impairment.

Speak with a local DUI attorney to discuss your DUI charges and learn more about DUI laws. A defense attorney can be invaluable after a DUI arrest and can help you understand why charges were filed despite your passing test result. A criminal defense attorney can offer legal advice and potentially help you avoid jail time or a lengthy driver’s license revocation.