Are Blood & Breath Tests for DUI Accurate?

Suppose you are pulled over on suspicion of driving under the influence (DUI) or because of a traffic violation, such as speeding, and the officer suspects you may be under the influence of alcohol. Perhaps the officer can smell the strong odor of alcohol on your breath, or perhaps you were slurring your words. Regardless of the officers “reasons” to suspect you, usually an officer would ask you to perform the standardized field sobriety tests.

If you don’t perform well on the field sobriety tests, which the officer uses to test things like your balance and coordination (the tests you see on television), usually the next step in the process is to have you submit to a chemical test in the form of a blood or breath test.

Under California’s Implied Consent Law, you agree to take chemical tests if an officer suspects you’re driving under the influence. If you refuse to take such a test, your driver’s license will be automatically suspended for one year, even if you had nothing to drink. In fact, your license would still be suspended for 12 months, even if you were found not guilty of DUI in court.

Three Types of Chemical Tests

In DUI cases, blood and breath tests are used most frequently; however, urine tests are used occasionally, especially when the driver is suspected of driving under the influence of drugs or alcohol and drugs. The general opinion of law enforcement, judges, and defense attorneys is that blood tests are the most accurate, followed by breath tests and finally, urine tests.

What are some things that can go wrong?

  • Laboratory errors
  • Improper preservation of blood samples
  • Breath testing device improperly calibrated
  • Faulty breath gas analysis reading (breath test)
  • And much more

While chemical tests can be useful tools to law enforcement officers, they are not infallible. If you were arrested for DUI, we urge you to contact our firm to speak to an experienced DUI defense attorney. We may be able to cast enough doubt to get your charges dismissed or reduced, thereby minimizing the effects of the DUI.

Contact the Law Offices of Virginia L. Landry, Inc. for a free case evaluation!

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  • Are Field Sobriety Tests Accurate? Read More