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Virginia DUI Breath Testing – Fairfax Criminal Lawyer on the 20 minute rule

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Virginia DUI breath testing- Fairfax criminal lawyer on the 20 minute rule- Image of liquor glass and keys

Virginia DUI breath testing- Fairfax criminal lawyer on the 20 minute rule

Virginia DUI breath testing- Fairfax criminal lawyer on the breathalyzer twenty-minute rule

Virginia DUI breath testing is always ripe for trial challenges. As a Fairfax DUI lawyer, I always explore this line of attack, including with the breathalyzer twenty minute rule. The Virginia Department of Forensic Science’s own breath test operator instructional manual (“DFS Manual“) provides the following concerning the 20 minute rule:

“Residual mouth alcohol must be considered when conducting a breath test. After drinking an alcoholic beverage, some alcohol (liquid or vapor) is temporarily retained in the mucous lining (the moist secreting tissues) of the mouth and the nasal passages… When deep lung air is exhaled, the vapor from any residual alcohol could be picked up by the deep lung air as it passes out of the mouth. Under these circumstances, mouth alcohol can cause a potentially greater concentration of alcohol in the breath sample, which in turn can cause a falsely higher BAC reading… Experiments have shown that residual mouth alcohol will be eliminated by normal body processes well within 20 minutes. For this reason, the subject must be observed for 20 minutes prior to providing a breath sample.” DFS Manual.

The Virginia DUI breath testing 20 minute rule is not satisfied without having the defendant open his or her mouth no less than 20 minutes in advance

Further regarding Virginia DUI breath testing, the DFS manual states: “The [Intox EC/IR II] operator should always inspect the subject’s mouth for any foreign objects. If found, they should be removed, and the subject must be observed for 20 minutes prior to providing a breath sample… Visual inspection of he mouth: Inspecting the mouth prior to conducting the observation period ensures that no foreign object(s) are within the mouth… Experiments have shown that residual mouth alcohol will be eliminated by normal body processes well within 20 minutes.”

How often do Virginia breath technicians bypass their obligation to have the defendant open his or her mouth at least 20 minutes before blowing into the breathalyzer machine?

Very frequently, I see that Virginia DUI breath technicians’ notes and reports are silent about whether they satisfied their obligation to have the defendant open his or her mouth at least 20 minutes before blowing into the Intox EC/IR II breathalyzer machine, to first check for the absence of foreign substances therein. Nonetheless, many of these same breath technicians testify that they conducted such an inspection, and know this to be the fact (even though absent from their otherwise detailed police report) not based on memory but based on regular practice. Praised be the breath technician who recently confirmed to me that he was not yet checking Virginia DWI defendants’ mouths for foreign substances at the time of my client’s arrest.

If the breath technician untruthfully claims s/he had me open my mouth at least 20 minutes before I blew into the breathalyzer machine, should I testify that the technician did not adhere to such a critical step?

If a Virginia DUI breath testing defendant testifies in opposition to the breath technician’s claim of checking inside the defendant’s mouth at least twenty minutes before starting the breathalyzer test, the Virginia caselaw allows the prosecutor to cross examine the defendant on any relevant aspect of the defendant’s case, rather than limiting such cross examination to the scope of the defendant’s own testimony. Consequently, it is first important, for instance, for the Virginia DUI defense lawyer and his or her client to determine whether his or her testifying will simply help the prosecutor obtain a conviction.

No Covid-19 exception applies to the DFS’s requirement for checking inside the defendant’s mouth at least 20 minutes before starting the breathalyzer test

The need for checking the Virginia DUI breath testing suspect’s mouth at least 20 minutes before blowing into the machine does not lessen with the reality of the coronavirus, and the Virginia DFS has not said otherwise in its breathalyzer procedure manual.

Fairfax DUI lawyer Jonathan L. Katz has successfully defended hundreds of people charged with DUI. Call 703-383-1100 for a free in-person consultation with Jon Katz about your court-pending case.