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  • John C. Whitbeck, Jr.


    John C. Whitbeck, Jr. practices in the following areas of law: Family Law, Divorce, Child Custody, Child Support, Visitation Rights, Adoptions, Spousal Support, Mediation, Arbitration, Relocation Cases, Domestic Violence, Criminal Law, DUI/DWI, Reckless Driving, All Felonies, All Misdemeanors, Juvenile Crimes, Mental Health Law, Civil and Business Litigation, Construction Litigation, Education Law, Election Law, Debt Collection, Consumer and Lemon Law.

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  • Ruth M. McElroy


    Ruth M. McElroy practices in the following areas of law: Family law, Divorce, Child Custody, Child Support, Visitation Rights, Adoptions, Spousal Support, Relocation Cases, Pre and Post Marital Agreements, Domestic Violence, Reckless Driving, DUI/DWI, Juvenile Crimes, Felony and Misdemeanor Crimes, Traffic Offenses, Debt Collection, Civil and Business Litigation. She serves the Virginia Court system as a Guardian ad litem.

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  • Jennifer D. Cisneros


    Jennifer D. Cisneros practices in the following areas of law: Family law, Divorce, Child Custody, Child Support, Visitation Rights, Adoptions, Spousal Support, Relocation Cases, Domestic Violence, Juvenile Crimes, Reckless Driving, DUI/DWI, Estate Planning, Wills and Probate, Trusts, Civil and Business Litigation and Debt Collection.

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Can ‘Inaccurate’ Breath Test Results Be a Defense Against DUI/DWI Charges in Virginia?


Police officers in Virginia often request a suspected drunk driver to submit to a blood or breath test, also known as a Breathalyzer test. These tests are popular tools in every police officer’s arsenal of standardized roadside tests to determine blood alcohol concentration (BAC) in the driver’s system.

These tests are used by prosecutors in courts to prove DUI and driving while intoxicated (DWI) charges. However, a New York Times investigation shows that breath tests can be inaccurate and flawed. If Breathalyzer tests cannot be trusted, here is the dilemma: a refusal to submit to a lawfully requested breath test can result in penalties, including a jail sentence in Virginia.

‘Inaccurate’ Breath Test Results as a Defense Against DUI/DWI Charges

For decades, breath tests have been a prominent part of a drunk driving investigation in criminal cases stemming from DUIs in Virginia.

After a Virginia police officer makes a traffic stop for a potential DWI, a breath test can be requested to determine the blood-alcohol content. The results of the Breathalyzer test will then be used as a key piece of evidence to pursue DUI or DWI charges against the driver.

However, what happens if the breath test results are flawed? A new investigation by the New York Times has triggered a heated debate about the accuracy of breath tests. The report, which says that breath test devices can be off by as much as 40%, concludes that the potential inaccuracy of breath test results could be part of a successful criminal defense against DUI charges.

How Breathalyzer Results Can Be ‘Flawed’

The investigation showed that Breathalyzer tests are prone to an inaccuracy after discussing breath tests with scientists, law enforcement officers, lawyers, and executives. In fact, the report determined that many people could have been convicted because:

  • A breath test device was improperly calibrated;
  • The device was not maintained properly;
  • The device was used incorrectly; or
  • The machine software was programmed inaccurately.

The investigation showed that police departments often lack knowledge of how these devices must be used, calibrated, and maintained.

Factors That Hinder Breath Test Results

Another problem surrounding breath tests in DUI convictions is that certain machines give inaccurate results when the driver burped or used:

  • A breath mint
  • Gum
  • Mouthwash
  • Toothpaste

These factors could hinder the results of Breathalyzer tests. Despite the reliability of breath tests facing scrutiny in Virginia and other states, they are still a significant part of the DUI investigation process.

Although blood tests are deemed the most accurate way to measure the amount of alcohol in a driver’s body, many police officers go with breath tests because they are faster and are presumed to be “more efficient.” Drivers who refuse a breath test during a DUI stop face separate charges for their refusal.

Penalties for DUI/DWI Charges and Refusal to Submit to Breath Test

Under Virginia’s implied consent statute, refusal of a lawfully requested breath test carries a one-year license suspension. A second-offense refusal is punishable by up to 12 months in jail, three years of license suspension, and up to $2,500 in fines.

DUI and DWI charges in Virginia carry a wide range of possible penalties, including fines, jail, license suspension, and a breath alcohol ignition interlock device (BAIID) being installed on the driver’s vehicle. Also, a driver convicted of DWI can face higher insurance rates and a negative mark on their driving record.

Since a DUI charge on your criminal record can have a negative impact on your future, you should call a skilled Leesburg DUI & DWI attorney. Contact Whitbeck Cisneros McElroy, PC, to discuss your situation and challenge the reliability of the breath test. Call at 703-997-4982 today.

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