Driving under the influence (DUI) or driving while intoxicated (DWI) charges are serious legal matters that can lead to severe penalties, including fines, jail time, and a suspension of your driver’s license. In many DUI and DWI cases, law enforcement officers rely on breathalyzer tests and field sobriety tests to determine if a driver is intoxicated. However, not all test results are always accurate or fair. That’s where skilled DUI/DWI defense lawyers come into play. They have the expertise to challenge breathalyzer and field sobriety test results, potentially reducing or even dismissing the charges against their clients.

In this article, we will explore how experienced DUI and DWI defense attorneys challenge the results of breathalyzer and field sobriety tests, discussing the methods they use to cast doubt on the accuracy of these tests. We’ll also highlight the importance of working with a reputable lawyer, especially if you’re facing DUI/DWI charges in San Antonio, and why seeking the top rated San Antonio DWI lawyer could make a difference in the outcome of your case.

Understanding Breathalyzer and Field Sobriety Tests

Before diving into how lawyers challenge these tests, it’s important to understand what they are and how they work.

  1. Breathalyzer Tests: A breathalyzer is a device used by police officers to measure the amount of alcohol in a person’s breath. It estimates the blood alcohol concentration (BAC) to determine if it exceeds the legal limit, which is typically 0.08% in most states.
  2. Field Sobriety Tests: These are physical and cognitive tests administered by officers on the roadside to evaluate a driver’s level of impairment. Common field sobriety tests include the walk-and-turn, the one-leg stand, and the horizontal gaze nystagmus (HGN) test, which checks for involuntary eye movement.

Both tests are widely used in DUI/DWI arrests, but they are not always reliable. Factors like improper administration of the tests, medical conditions, and environmental influences can impact the results, and skilled defense attorneys can use these factors to challenge the validity of the tests.

How Lawyers Challenge Breathalyzer Results

Breathalyzer tests are often perceived as scientific and highly accurate, but they are far from foolproof. There are several ways that DUI/DWI lawyers can question the results of a breathalyzer test in court:

1. Questioning the Maintenance and Calibration of the Device

Breathalyzers require regular maintenance and calibration to function properly. If the machine used during a DUI stop has not been calibrated according to schedule or was not maintained correctly, its accuracy could be compromised. A defense attorney can request records of the machine’s maintenance history. If the records show that the device wasn’t properly maintained, the lawyer may argue that the breathalyzer reading is unreliable.

2. Challenging the Officer’s Training

Officers must be properly trained in the use of breathalyzer devices. If the officer who administered the test didn’t follow proper procedures or wasn’t adequately trained, the test results may be inaccurate. A lawyer can investigate the officer’s training records and cross-examine them to reveal any inconsistencies in how the breathalyzer was administered.

3. Medical Conditions

Certain medical conditions can affect breathalyzer results. For instance, people with acid reflux or gastroesophageal reflux disease (GERD) may have higher levels of alcohol in their breath, even if their BAC is below the legal limit. Additionally, diabetics can produce acetone, a chemical that can interfere with breathalyzer readings and cause false positives. An attorney can use medical records to argue that the breathalyzer results were influenced by the driver’s health conditions.

4. Mouth Alcohol

Breathalyzers are designed to measure alcohol in deep lung air, not the alcohol in the mouth. However, if a person has recently used mouthwash, taken medication, or burped, residual alcohol in the mouth could lead to an inflated reading. Lawyers may argue that mouth alcohol, rather than blood alcohol, caused the elevated BAC result.

5. Timing of the Test

Alcohol levels in the body fluctuate over time, and it takes time for alcohol to be absorbed into the bloodstream after drinking. A breathalyzer test conducted shortly after a person has been drinking might give a lower reading than their actual BAC. Conversely, if there was a delay between the traffic stop and the breathalyzer test, the driver’s BAC may have increased during that time. Defense lawyers can use these timing factors to argue that the test results were not representative of the driver’s BAC at the time they were operating the vehicle.

How Lawyers Challenge Field Sobriety Tests

Field sobriety tests are even more subjective than breathalyzer tests and are often easier to challenge in court. Defense attorneys frequently attack the reliability of field sobriety tests in DUI/DWI cases, as these tests are based on the officer’s interpretation of the driver’s performance, which can be influenced by several factors unrelated to intoxication. For those facing such charges, consulting a top rated San Antonio DWI lawyer can provide essential guidance and support in addressing these issues effectively.

1. Physical or Medical Conditions

Many people have physical or medical conditions that can affect their ability to perform field sobriety tests. For example, individuals with injuries, arthritis, or balance disorders may struggle to complete tasks like the walk-and-turn or the one-leg stand. Additionally, people with inner ear problems may not be able to maintain their balance, even if they are completely sober. A defense lawyer can present medical evidence to show that the driver’s poor performance was due to a medical condition, not intoxication.

2. Environmental Factors

Field sobriety tests are typically conducted on the side of the road, which can be uneven or sloped. Poor lighting, inclement weather, and traffic passing by can also make it difficult for a driver to perform well on these tests. A skilled defense attorney can argue that the conditions of the roadside environment contributed to the driver’s poor performance, not alcohol impairment.

3. Nervousness or Anxiety

Being stopped by the police can be an intimidating experience, especially for someone who has never been pulled over before. Anxiety and nervousness can affect a person’s ability to perform field sobriety tests. For example, a driver might lose their balance because they are nervous about being arrested, not because they are intoxicated. A lawyer can argue that nervousness caused the driver to fail the test.

4. Improper Instructions

Field sobriety tests must be administered according to strict guidelines. If the officer failed to explain the test properly or gave unclear instructions, the driver might have misunderstood what they were supposed to do. A defense attorney can argue that the driver’s failure to follow instructions was the result of the officer’s poor communication, rather than impairment.

5. Officer Bias

Field sobriety tests rely heavily on the officer’s observations and interpretation of the driver’s performance. However, if the officer has already made up their mind that the driver is intoxicated, they might interpret the test results unfairly. For example, if the officer expects the driver to fail, they might report minor mistakes or imperfections as evidence of impairment. Defense lawyers can challenge the officer’s objectivity, especially if there is evidence of bias or misconduct.

The Role of Expert Witnesses in Challenging Test Results

In many DUI/DWI cases, defense attorneys bring in expert witnesses to support their challenges to breathalyzer and field sobriety test results. These experts may include toxicologists, who can testify about the limitations of breathalyzer technology, or medical professionals, who can explain how certain health conditions might have influenced the test results. Additionally, accident reconstruction experts or former police officers who are familiar with DUI/DWI procedures can provide testimony about how the tests should have been conducted and whether the proper protocols were followed.

By presenting expert testimony, defense attorneys can cast doubt on the accuracy of the test results and create reasonable doubt about their client’s guilt. In some cases, the testimony of these experts can lead to the dismissal of the charges altogether.

The Importance of Hiring a Skilled DUI/DWI Lawyer

If you’ve been charged with DUI or DWI, it’s crucial to seek legal representation from a lawyer who specializes in these cases. DUI/DWI laws are complex, and the penalties for a conviction can be severe. An experienced attorney understands how to navigate the legal system and can craft a defense strategy that challenges the evidence against you.

In San Antonio, for example, working with the top rated San Antonio DWI lawyer can give you a significant advantage. These attorneys are familiar with the local courts, prosecutors, and judges, and they know how to build a strong defense that protects your rights. Whether it’s questioning the validity of breathalyzer results, exposing flaws in field sobriety tests, or presenting expert testimony, a skilled DUI/DWI lawyer will fight to get the best possible outcome for your case.

Conclusion

Breathalyzer and field sobriety tests are often used as key evidence in DUI/DWI cases, but they are not infallible. There are numerous ways to challenge the accuracy and reliability of these tests, from questioning the maintenance of the breathalyzer device to highlighting medical conditions or environmental factors that could have influenced the results. A skilled DUI/DWI lawyer will know how to exploit these weaknesses and build a strong defense on your behalf.

If you’re facing DUI or DWI charges, it’s essential to seek the guidance of an experienced attorney. Working with a top rated San Antonio DWI lawyer can make all the difference in your case, helping you avoid severe penalties and protect your driving record. Whether through challenging test results or negotiating with prosecutors, a knowledgeable lawyer will work tirelessly to ensure the best possible outcome for your case.