Can prosecutors use a roadside breathalyzer result to prove underage drinking, public intoxication, or alcohol use by an interdicted person?

Plain-English summary

Fredericksburg's Commonwealth's Attorney asked the AG a practical evidentiary question: when an officer uses a roadside "preliminary breath test" device (the Alco-Sensor or a similar handheld), can the result be introduced as evidence to prove three non-DUI alcohol offenses? Specifically:

1. Underage possession of alcohol.
2. Possession or consumption of alcoholic beverages by a person who has been interdicted (a judicially declared habitual drunkard who is forbidden alcohol).
3. Public intoxication.

The AG said yes, subject to two conditions: trial-judge discretion and proper foundation.

The starting point, the AG noted, is that admissibility of evidence rests within the broad discretion of the trial court. There are exceptions, the most relevant being that the law expressly prohibits the admission of PBT results when a driver is suspected of certain driving offenses. That ban is well known in Virginia DUI practice: a PBT taken at the scene is for the officer's probable-cause determination, not for trial use against the DUI defendant. The prosecutor needs the full evidentiary breath test (or blood test) administered after arrest at the station.

But that prohibition is tied to the driving offenses. The General Assembly didn't write a parallel prohibition for the three offenses the Fredericksburg prosecutor asked about. The AG reasoned that when one statute makes a specific prohibition, the absence of the same prohibition in another statute is evidence the legislature intended no ban where it is not referenced. So the silence in the underage-alcohol, interdicted-person, and public-intoxication offenses cuts in favor of admissibility.

That doesn't mean PBT results automatically come in. The AG stressed the need for a proper foundation: evidence that the device was properly calibrated and reliable. He noted that even in civil cases the court has required proof of calibration and reliability before admitting test results. So while there's no statutory bar to PBT evidence in these three offense categories, the prosecutor still has to put on enough proof that the machine was working properly.

This is a short, useful opinion. The practical effect: prosecutors trying underage-drinking or public-intoxication cases (and the much rarer interdicted-person cases) can use the same Alco-Sensor result that would be inadmissible in a DUI case from the same arrest. Defense attorneys will need to challenge the foundation, not the categorical admissibility.

Currency note

This opinion was issued in 2013. Subsequent statutory amendments, court decisions, or later AG opinions may have changed the analysis. Treat this page as historical context, not current legal advice. Verify current law before relying on any specific rule, deadline, or remedy mentioned here.

Common questions

What is a preliminary breath test (PBT)?
A roadside breath analyzer, typically the Alco-Sensor IV in Virginia, used by an officer to estimate a suspect's blood alcohol concentration. PBTs are smaller, less accurate, and less rigorously calibrated than the evidentiary instruments (Intox EC/IR II) used at police stations.

Why is the PBT inadmissible in DUI prosecutions?
The law expressly says so for drivers suspected of certain driving offenses. The General Assembly designed the PBT as a probable-cause tool, not a trial-level instrument. For DUI, the Commonwealth must use the post-arrest evidentiary breath test or blood test.

What is "interdiction"?
A court order declaring a person a "habitual drunkard" and forbidding the person from possessing or consuming alcohol. Once interdicted, the person can be prosecuted for any subsequent possession or consumption.

What is the "proper foundation" the AG mentions?
Foundation, in evidence law, is the threshold proof that an item or test is reliable enough for the factfinder to consider it. The AG pointed to the requirement, applied even in civil cases, that the proponent show the machine was properly calibrated and reliable. In practice that can include proof that the device was calibrated to specification, that the officer was trained in its use, and that the result was recorded contemporaneously.

Can a defense attorney still keep the PBT out?
Yes, by attacking the foundation. If the prosecution can't establish that the device was working properly or that the officer used it correctly, the trial judge has discretion to exclude the result. The AG opinion doesn't change that; it just confirms there's no categorical bar.

Does this apply to BUI (boating under the influence) or DUI commercial vehicle cases?
The opinion doesn't address those. The § 18.2-267 PBT ban applies to driving offenses under § 18.2-266 and similar; whether parallel bars apply to BUI or commercial vehicle DUI would need a separate statutory analysis.

Background and statutory framework

The three offenses the prosecutor asked about, all named in the opinion without citing their code sections:

• Underage possession of alcohol: makes it unlawful for a person under 21 to possess or consume alcoholic beverages.
• Possession or consumption by an interdicted person: prohibits a person who has been judicially interdicted (declared a habitual drunkard) from possessing or consuming alcohol.
• Public intoxication.

The DUI PBT bar: the opinion notes that the law expressly prohibits admission of a preliminary breath test result when a driver is suspected of certain driving offenses. The opinion does not print the section number for that bar.

The interpretive principle: when the General Assembly imposes a specific prohibition in one statute and omits the same prohibition in another, the omission is evidence the legislature intended no ban where it is not referenced. This is the reasoning the AG invoked.

The foundation rule: the opinion states that the proponent of breath-test evidence must show proper calibration and reliability of the machine, a requirement applied even in civil cases. It cites no case by name.

Citations

• Va. Code § 2.2-505 (authority for the advisory opinion)

Source

• Landing page: https://www.oag.state.va.us/annual-reports-opinions/official-opinions
• Original PDF: https://www.oag.state.va.us/files/Opinions/2013/12-111_Jenkins.pdf

Original opinion text

COMMONWEALTH of VIRGINIA
Office of the Attorney General
Kenneth T. Cuccinelli, II
Attorney General

June 7, 2013

900 East Main Street
Richmond, Virginia 23219
804-786-2071
FAX 804-786-1991
Virginia Relay Services
800-828-1120
7-1-1

The Honorable La Bravia J. Jenkins
Commonwealth's Attorney
City of Fredericksburg
Post Office Box 886
Fredericksburg, Virginia 22404-0866

Dear Ms. Jenkins:

I am responding to your request for an official advisory opinion in accordance with § 2.2-505 of the Code of Virginia.

Issue Presented

You have asked whether the results of preliminary breath tests (Alco-Sensor or like device) are admissible evidence for the offenses of underage possession of alcohol, possession, or consumption of alcoholic beverages by an interdicted person, and public intoxication.

Response

It is my opinion that the results of the preliminary breath tests you describe may be admissible for the offenses of underage possession of alcohol, possession, or consumption of alcoholic beverages by an interdicted person and public intoxication at the discretion of the trial judge and subject to the proper foundation.

Applicable Law and Discussion

"The admissibility of evidence is within the broad discretion of the trial court." There are obvious exceptions such as when the legislature has prohibited certain evidence. For example, the law expressly prohibits the admission into evidence of the results of a preliminary breath test when a driver is suspected of certain driving offenses. No such prohibition exists for underage possession of alcohol, possession or consumption of alcoholic beverages by an interdicted person and public intoxication. When one statute makes a specific prohibition, the lack of such specific prohibition in another statute is evidence that the General Assembly intended that a prohibition not exist where it is not referenced.

Nonetheless, it is also important to have a proper foundation in admitting preliminary breath test analysis into evidence. Even in civil cases the court has required evidence of proper calibration and reliability of the machine used in order to admit the test results. Therefore, an important element in the admissibility of the preliminary breath test is the foundation that the machine was working properly.

Conclusion

Accordingly, it is my opinion that results of the preliminary breath tests you describe may be admissible for the offenses of underage possession of alcohol, possession or consumption of alcoholic beverages by an interdicted person and public intoxication at the discretion of the trial judge and subject to the proper foundation.

With kindest regards, I am

Kenneth T. Cuccinelli, II
Attorney General