DUI Defenses: Exploring Common Strategies To Challenge DUI Charges

While it can feel like the end of the world when you get arrested for DUI, your life is not over. You face severe consequences for driving under the influence of alcohol. They include expensive fines, community service, jail time, and driver’s license suspension.

However, you also have a right to a trial. You or your DUI lawyer can present one or more defenses during this trial. This could mitigate charges or prove you innocent. Your legal representation may use one or more of these defenses when responding to the prosecution’s case.

Presumption of Innocence and Burden of Proof

In U.S. criminal court, you start with a presumption of innocence for your DUI charge. The prosecution has the burden of proof to show that you committed the crime of DUI/DWI. You or your lawyer then present a legal defense in response.

This distinction is crucial because you do not have to prove your innocence. Instead, you are showing the lack of viability in the prosecutor’s arguments. It also means you have a right to defend yourself. Robert Reiff is a criminal defense attorney in Miami, Florida. He finds that clients commonly do not realize they have a right to a defense for DUI charges or the number of defense arguments available. “I think many people think that you can’t defend the DUI, and that’s not correct. I mean, there’s a lot that can be done.”

Challenging the Traffic Stop 

The first consideration is the legality of the traffic stop. If the officer did an improper or unlawful traffic stop, everything that follows could be potentially inadmissible. Without this evidence, there is no basis for the DUI charge. A common argument with this type of defense is that the police officer did not have probable cause or reasonable suspicion to initiate the traffic stop.

Another common defense is that the law enforcement officer illegally obtained evidence. This happens when they perform an improper search and seizure. This would violate your Fourth Amendment constitutional rights. If this is the case, the prosecutor cannot use the illegally obtained evidence in your trial. It will become more challenging for them to secure a DUI conviction without the supporting evidence.

Reiff explains this process and how it relates to your right to drive. “All states have due process. This means that even though driving is a privilege and not a right, if they take away your privilege to drive, they have to give you some semblance of due process to challenge the validity of that suspension.”

Questioning Field Sobriety Tests (FSTs)

A common method for determining intoxication level is field sobriety tests. These are physical tests that the officer has a driver perform. Examples include standing on one leg and counting, walking a straight line with a turnaround and comeback, or horizontal gaze testing. The officer will explain the test and expect the individual to perform it perfectly.

There are several potential problems with this test. It does not directly measure your blood alcohol content (BAC). The tests don’t account for individuals varying levels of physical ability. Whether you pass the field testing is also highly subjective based on the officer’s opinion of your performance.

Many individuals struggle to follow directions or successfully complete tasks when completely sober. This makes them unreliable when determining BAC level.

Problems Analyzing Breathalyzer Tests and Blood Tests

Chemical tests are a common method for creating evidence against an individual suspected of DUI. A breath test requires the driver to breathe into a device that will measure the alcohol level in the air coming from the individual’s lungs. A blood test will measure the amount of alcohol in the individual’s blood.

If you perform either or both of these tests, your DUI defense lawyer will ask for the maintenance logs and records of the devices used to perform these tests.

Faulty Test Equipment

Testing equipment needs to be routinely recalibrated for accuracy. If the equipment used to test your BAC has not received proper calibration, your test results could be inaccurate. This can call into question the reliability of the prosecution’s evidence against you. While faulty equipment won’t automatically drop your charges or prove your innocence, it is a possible defense that will benefit your case.

Inaccurate Test Results

Even with a properly calibrated machine, accurate results rely on the officer operating the machine correctly. If they did not receive proper training, this could call into question the results. The prosecutor needs to prove your guilt beyond a reasonable doubt. So, improper operation could create enough doubt to create an effective defense.

Reiff explains that human operational error is a common problem. “The problem with breath testing, for instance, is that they’re supposed to look for deep lung samples, which would be accurate, but to get deep lung samples, you have to perform the test correctly. This doesn’t always happen, and the officer gets an incorrect BAC reading.”

Medical Conditions and Other Factors That Complicate Chemical Testing

Not all humans are the same; medical or physical conditions can impact how we drive, perform sobriety tests, or score on chemical tests. Despite not drinking, you could fail tests or receive a score indicating a BAC above the legal limit.

Some medications or acid reflux can be a defense for your breathalyzer test results. Medical conditions like diabetes, the keto diet, or medications can impact how your body metabolizes alcohol. This can result in a delayed BAC level. Your chemical test results would not accurately represent your BAC when operating your vehicle.

Blood testing is also subject to inaccuracies due to medical conditions. If you strictly follow a keto diet and achieve ketosis, your breath could have higher concentrations of auto-generated isopropyl. Breathalyzers could read this is alcohol on your breath. Other potential issues include lap band surgery recipients, partition ratio of blood to breath, and metabolism. These are all possible defenses because they use a generalized standard across all individuals. The problem is not everyone fits within the standard all of the time. When outside of the average standard, you can return inaccurate BAS results.

Reiff speaks about how even minor medical conditions can impact your results. “If you have any illness, if you have anxiety or stress, and even your gender can cause your internal heat to go higher than the average. The machine itself has a built-in [error range] of ±.01. Combine these factors, and you have the potential for an inaccurate result.”

As Reiff notes, breathalyzers have a built-in error allowance range that can result in measurements that are slightly off. Your body chemistry can then increase this error range by impacting your test results. This can mean that your breathalyzer test reading could be inaccurate for your actual blood alcohol level. You could then face harsher criminal charges and punishment based on this inaccurate reading.

Inadequate Miranda Warnings 

If the arresting officer failed to give your Miranda rights, this may or may not impact your case. Miranda rights apply to your statements after your DUI arrest during questioning. In many cases, the officers do not need to question the individual. They may not give you your Miranda rights if they don’t question you. They may feel they have enough evidence to convict you without your statements.

In contrast, if the officers question you post-arrest, they will need to give you your Miranda rights. Otherwise, any statements made during questioning will be inadmissible in court. This does not mean your DUI charges get automatically dropped or dismissed.

Get an Experienced Criminal Defense Lawyer

DUI laws are in place to prevent drunk driving. Facing DUI charges does not mean you are automatically guilty. A DUI defense attorney works to protect their client’s legal and constitutional rights, mitigate the negative consequences of a DUI arrest, and obtain the best possible outcome of a DUI case. They may use a combination of these DUI defense strategies as part of their representation. An experienced DUI attorney can analyze your DUI case and determine the best defense approach for the most favorable outcome.

Visit the Super Lawyers directory to begin your search for an experienced DUI defense attorney.