Breathalyzer and blood tests are commonly used by law enforcement to determine a driver’s blood alcohol content (BAC) and establish impairment. While these tests are scientifically grounded, they are not infallible. Understanding the science behind these tests, their potential inaccuracies, and how they can be challenged in court is essential for anyone facing DUI charges. Consulting a Colorado DUI attorney can provide the necessary expertise to navigate these complexities effectively.
The Science Behind Breathalyzer Tests
Breathalyzer tests measure the alcohol concentration in a person’s breath to estimate their BAC. When alcohol is consumed, it is absorbed into the bloodstream through the stomach and small intestine. As blood flows through the lungs, alcohol evaporates into the alveolar air and can be measured in exhaled breath. Breathalyzers calculate BAC using a ratio that assumes a standard relationship between the concentration of alcohol in the breath and in the blood.
- Infrared Spectroscopy: Some breathalyzers use infrared light to detect alcohol molecules in the breath sample. The presence of alcohol absorbs specific wavelengths of infrared light, and the device measures this absorption to estimate BAC.
- Fuel Cell Technology: Other breathalyzers use fuel cells that produce an electrical current when exposed to alcohol. The strength of the current correlates with the alcohol concentration, providing a BAC estimate.
Potential Inaccuracies of Breathalyzer Tests
Despite their scientific basis, breathalyzer tests can produce inaccurate results due to various factors:
- Calibration Issues: Breathalyzers require regular calibration to ensure accuracy. An improperly calibrated device can yield incorrect BAC readings.
- Mouth Alcohol: Residual alcohol in the mouth from recent consumption, mouthwash, or medication can artificially inflate BAC readings.
- Breath Temperature: Breathalyzer accuracy can be affected by the temperature of the breath sample. Higher temperatures can result in higher BAC estimates.
- Medical Conditions: Conditions like acid reflux or diabetes can produce compounds that interfere with breathalyzer readings, leading to false positives.
The Science Behind Blood Tests
Blood tests directly measure the alcohol concentration in a person’s bloodstream. They are generally considered more accurate than breathalyzer tests but are not without potential issues. Blood samples are typically drawn by medical professionals and analyzed in a laboratory.
- Gas Chromatography: This is the most common method for analyzing blood alcohol content. The blood sample is vaporized, and the components are separated in a gas chromatograph. The amount of alcohol is then measured and converted into a BAC reading.
Potential Inaccuracies of Blood Tests
While blood tests are often viewed as the gold standard for BAC measurement, they can still be subject to inaccuracies:
- Contamination: Blood samples can be contaminated if not properly handled or stored, leading to erroneous results.
- Fermentation: Improper storage can cause blood samples to ferment, artificially increasing alcohol levels.
- Timing: The timing of the blood draw relative to when the person was driving can affect BAC readings. Alcohol absorption and elimination rates vary, and a delay in testing can result in higher or lower BAC levels than when the person was driving.
Challenging Breathalyzer and Blood Test Results in Court
A Colorado DUI attorney can challenge the results of breathalyzer and blood tests in several ways:
- Calibration Records: Attorneys can request maintenance and calibration records for the breathalyzer device used. If the device was not properly maintained, its results may be deemed unreliable.
- Administration Protocol: Breathalyzer tests must be administered according to specific protocols. Any deviation from these procedures can be grounds for challenging the results.
- Medical Conditions: Demonstrating that a medical condition or medication could have affected the test results can cast doubt on their accuracy.
- Chain of Custody: For blood tests, the chain of custody must be meticulously documented. Any gaps or mishandling in the sample’s custody can lead to questions about its integrity.
- Expert Testimony: A DUI attorney can call on medical or forensic experts to testify about the potential inaccuracies and limitations of the testing methods used.
The Role of a Colorado DUI Attorney
Navigating the complexities of DUI charges requires specialized legal expertise. A Colorado DUI attorney can:
- Analyze Evidence: Scrutinize the evidence and identify potential inaccuracies or procedural errors in breathalyzer and blood test administration.
- Develop Defense Strategies: Formulate defense strategies based on scientific knowledge and legal precedents to challenge the reliability of test results.
- Negotiate: Engage with prosecutors to negotiate plea deals or alternative sentencing options that may mitigate the consequences of a DUI conviction.
- Represent in Court: Provide robust representation in court, ensuring that your rights are protected and that the evidence is thoroughly examined.
Breathalyzer and blood tests are critical tools in DUI enforcement, but they are not infallible. Understanding their scientific basis, potential inaccuracies, and how they can be challenged in court is crucial for anyone facing DUI charges. Consulting a Colorado DUI attorney can provide the necessary expertise to navigate these challenges effectively. With the right legal support, you can work towards the best possible outcome in your case, ensuring that the evidence against you is thoroughly scrutinized and that your rights are upheld.
