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Challenging Breath Test Results in DUI Cases: How to Undermine the Prosecution’s Evidence

Challenging Breath Test Results in DUI Cases

How to Undermine the Prosecution’s Evidence

Driving Under the Influence (DUI) charges in Nevada are serious and carry severe penalties, including fines, license suspension, and even jail time. One of the most common pieces of evidence used by the prosecution in DUI cases is the result of a breath test. While these tests are widely perceived as accurate, they are not infallible. This blog post will explore the various ways in which breath test results can be challenged, undermining the prosecution’s case and potentially leading to a dismissal or reduction of charges.

Understanding How Breath test Tests Work

A breath test in Nevada is done on a machine called the Intoxilyzer 8000.  This is a large blocky machine, resembling an early 1980s personal computer.  It is often referred to as a “breathalyzer” – – which is an incorrect term, as that is a brand name and not used in Nevada.  The Intoxilyzer – – referred to from here on as a breath test machine, is a device used to estimate Blood Alcohol Content (BAC) from a breath sample. In Nevada, a BAC of 0.08% or higher is considered “over the legal limit for most drivers,” while a BAC of 0.04% or higher is the limit for commercial drivers. For drivers under 21, any detectable BAC can result in a DUI charge.

Breath tests work by measuring the amount of alcohol in the breath and then using a formula to estimate the BAC. However, this process is based on several assumptions that may not hold true in every situation, leading to potentially inaccurate results.

Common Challenges to Breath test Evidence

Improper Calibration and Maintenance

Breath test machines must be regularly calibrated and properly maintained to ensure accuracy. If the device was not calibrated correctly or maintained according to the manufacturer’s specifications, the results may be inaccurate. The defense can request maintenance and calibration records to identify any lapses that could have affected the test results.

Operator Error

Only trained and certified personnel are authorized to administer breath test tests in Nevada. Operator error, such as improper handling or incorrect operation of the device, can lead to inaccurate results. If the operator did not follow standard procedures, the test results could be challenged.

Medical Conditions and Medications

Certain medical conditions, such as gastroesophageal reflux disease (GERD), diabetes, or hypoglycemia, can produce false positives on a breath test test. Additionally, some medications contain alcohol or can interfere with the body’s metabolism, affecting the breath test results. The defense can present medical records or expert testimony to show that the BAC result was affected by these factors rather than actual alcohol consumption.

 Mouth Alcohol Contamination

Residual alcohol in the mouth can lead to artificially high BAC readings. This can occur if the defendant burped, regurgitated, or used mouthwash shortly before the test. Nevada law requires that the officer observe the defendant for at least 15 minutes prior to administering the breath test to ensure no mouth alcohol is present. If this observation period was not properly conducted, the results may be deemed unreliable.

 Rising Blood Alcohol Defense

Alcohol absorption into the bloodstream takes time. If a defendant consumed alcohol shortly before driving, their BAC could have been below the legal limit while driving but risen above it by the time the test was administered. This is known as the “rising blood alcohol” defense. Expert testimony can be used to explain how the BAC at the time of testing was not reflective of the BAC while driving.

 Faulty Breath test Device

Breath test devices, like any electronic equipment, can malfunction. If there is evidence that the device was defective, the results could be deemed inadmissible. This can be proven through expert analysis or a review of the device’s maintenance records.

 Interference from External Substances

Substances such as mouthwash, breath sprays, or even certain foods can contain alcohol and produce false positives. The defense can argue that the BAC reading was influenced by these substances rather than alcohol consumption.

 Incorrect Test Timing

Nevada law requires that the breath test be administered within two hours of the alleged offense. If the test was conducted outside of this timeframe, it may not accurately reflect the defendant’s BAC at the time of driving. In such cases, the defense can argue that the results should not be considered as evidence.

 Legal Procedures for Challenging Breath test Evidence

To successfully challenge breath test evidence, the defense must follow proper legal procedures, including:

Discovery Requests: The defense can request calibration logs, maintenance records, and training certifications for the officer who administered the test. This information can be used to identify any procedural errors or issues with the equipment.

Pre-Trial Motions: The defense can file pre-trial motions to suppress the breath test results if there is evidence of improper calibration, operator error, or other factors affecting the test’s validity.

Expert Testimony: In many cases, the defense may need to hire an expert witness, such as a forensic toxicologist, to testify about the unreliability of the breath test results due to specific factors in the case.

Cross-Examination: During trial, the defense can cross-examine the arresting officer and challenge their knowledge and adherence to proper testing procedures. Any inconsistencies or errors in the officer’s testimony can cast doubt on the reliability of the breath test results.

Challenging breath test results in Nevada DUI cases requires a comprehensive understanding of the testing procedures, potential sources of error, and legal strategies. A successful defense can lead to the suppression of key evidence, reducing the chances of a conviction or resulting in a lesser charge.

If you or a loved one is facing DUI charges in Nevada, it is essential to have experienced legal representation to navigate these complex issues. Attorney Josh Tomsheck at Hofland & Tomsheck is a nationally certified criminal trial attorney and a member of the National College for DUI Defense. Contact the firm today for a consultation to discuss your case and explore your legal options.

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