Home » Blog » DWI / DUI » Virginia DWI BAC testing requires 20 minute advance mouth check

Virginia DWI BAC testing requires 20 minute advance mouth check

Call Us: 703-383-1100

Virginia DWI BAC testing- Image of alcohol glass

Virginia DWI BAC testing is invalid if the breath test operator does not have the suspect open his or her mouth at least 20 minutes before blowing into the breathalyzer machine, says Fairfax DWI lawyer

Virginia DWI BAC (blood alcohol concentration) testing is unreliable if the breath technician does not at least twenty minutes before testing, check the inside of the suspect’s mouth for foreign substances. As a Fairfax DUI lawyer, I know that post-arrest breathalyzer testing is supposed to check not for mouth alcohol but for deep lung alcohol. This makes essential a mouth check at least twenty minutes before blowing into the machine, both because the Virginia Department of Forensic Science (DFS) Intox EC/IR II breathalyzer procedures require such checking (and the breath technician’s signed attestation clause asserts that s/he has followed DFS procedures) but also because the presence of foreign substances in the suspect’s mouth can trap alcohol in the oral cavity, and thus upend the need for BAC testing to check for deep lung alcohol in Virginia DUI cases prosecuted under Virginia Code § 18.2-266

The DFS Breath Test Operator Instructional Manual (Breathalyzer Manual) for Virginia DWI BAC testing is clear that this 20 minute rule necessitates checking the suspect’s mouth, and not simply observing whether the arrestee puts anything in his or her mouth for at least twenty minutes before blowing into the machine: “The Department of Forensic Science operator and instrument protocols, along with the Intox EC/IR II have several safeguards in place to prevent an inaccurate analysis and to ensure a valid test. Visual inspection of the mouth: Inspecting the mouth prior to conducting the observation period ensures that no foreign object(s) are within the mouth. If found, the foreign object(s) should be removed and a 20 minute observation period observed.” Breathalyzer Manual at 22 (emphasis added). The Breathalyzer Manual for over a full page underlines the necessity of this minimum 20 minute observation period, thereby not making this observation period a mere formality, but an essential step in breathalyzer testing. Id at 22.

The Breathalyzer Manual is only 40 pages. For breath test operators not to fully understand and follow the manual is a travesty of justice.

For Virginia DWI BAC testing, the breath technician signs the following attestation on the certificate of blood alcohol analysis that reports the results of breathalyzer testing: “I certify that the… test was conducted in accordance with the [DFS’s] specifications…” The breath technician has no business signing that attestation clause if s/he has not followed the essential DFS dictate to inspect the suspect’s mouth at least twenty minutes before blowing into the machine. Nonetheless, two breath technicians recently talked as if nothing was wrong (unless they were hoping I would not catch on that anything was wrong) when their answer to my asking whether they had my client open their mouth at least 20 minutes before providing a breathalyzer sample, was that they observed my client talking. Since when is watching a person talking a sufficient opportunity to have them open their mouth? It is not a sufficient opportunity nor sufficient substitute. Instead, my foregoing question possibly makes some breath technicians — always law enforcement officers in the jurisdictions where I practice — be concerned whether they might get the equivalent of being busted on the witness stand. The more typical answer to my foregoing question is: “I always have them open their mouth at least twenty minutes before blowing, so I don’t need to mention that in my report.” “I probably had them open their mouth.”

If a breath technician cannot follow a 40-page manual for Virginia DWI BAC testing, the operator’s testimony is suspect at the very least

What is the proper remedy for the breath test operator’s failure with Virginia DWI BAC testing to abide by the twenty minute rule? It is to disregard the BAC results, because to do otherwise lets the breath technician slide for attesting to having followed DFS specifications when they in fact deviated materially from those specifications. Furthermore, if the breath test operator did not follow that twenty minute dictate, that unravels any reliability of their testing procedure.

Sloppy BAC testing is the very definition of reasonable doubt

Shoddy police work — including violation of the twenty minute rule for Virginia DWI BAC testing — can by itself generate reasonable doubt in the trial factfinder, whether that be the trial judge at a bench trial or the jury. The law requires presuming criminal defendants innocent, and keeps them in that innocent status unless and until the factfinders are convinced after the conclusion of the evidence, jury instructions and closing argument that guilt has been proven beyond a reasonable doubt. Do not let police get away with shoddy work, which can be at the expense of the liberty and reputation of the defendant.

Fairfax DUI lawyer Jonathan Katz focuses a substantial portion of his law practice on DWI defense. Be ready to see Jon Katz’s extensive ability, experience and knowledge with such defense, through a free in-person confidential consultation about your court pending case. Call 703-383-1100 to schedule your appointment with Jon.