Are Blood Tests More Accurate Than Breathalyzers?

Are Blood Tests More Accurate Than Breathalyzers?

Yes. As BACtrack explains:

Generally, breath tests are not as accurate as blood tests,” and “analysis of a blood sample for BAC is generally more accurate than breath and urine tests.” BAC stands for blood alcohol content, so it only makes sense that blood tests are the most accurate way to test someone’s BAC.

In most cases, however, you must consent to a blood test. Excluding certain situations, authorities need permission or a warrant to draw your blood. As a result, most officers use field sobriety tests and breathalyzers during traffic stops.

Why Are Breath Tests Less Accurate?

Breath testing is an indirect way of measuring someone’s BAC. Breathalyzers do not distinguish one individual from another, which may result in inaccurate readings. Further, breath tests are susceptible to environmental factors, and the presence of certain products can skew the results. Sometimes, a person’s diet can interfere with the results, as well. If someone just used mouthwash, consumed a mint, or ate food prepared with cooking wine, they might appear to have a higher BAC during a breath test.

In serious cases, such as drunk driving accidents, authorities may perform a breath test in the field and a blood test at the station. If officers rely on the results of a breath test, your criminal defense attorney should double-check for signs that environmental factors led to false results.

Why Do Authorities Use Breath Tests Even Though They Are Less Accurate?

Breath tests are less invasive than blood tests and easier to administer. They also produce results immediately, so authorities can decide whether to arrest someone during a traffic stop instead of taking them to the hospital for blood testing and waiting for laboratory results.

If a driver is already in the hospital with accident-related injuries, however, officers will ask the hospital to test the driver’s BAC.

Can I Fight a Blood Test?

Just like breath tests, blood tests are not always perfect. Your defense attorney may be able to argue that the blood was stored incorrectly, which results in fermentation and misleadingly high BACs, or emphasize the fact that your BAC might have increased in between your traffic stop and having your blood drawn. If your BAC is marginally above the legal limit, this “rising blood alcohol defense is more likely to be successful.

The best defense to blood test results is procedural. If officers draw your blood without a warrant, the results may be inadmissible in court.

Need Help?

Whether officers used a breath test or a blood test, you should not try to fight DWI charges alone. Instead, contact an experienced criminal defense attorney like Foley Griffin, LLP. Our trusted litigators have more than 75 years of combined experience, and we know how to protect our clients.

For help limiting your exposure to charges and convictions and avoiding jail time and other consequences, please call us at (888) 966-8480 or contact us online. Free consultations.

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