Foundational Issues in Virginia DUI Cases: What the Commonwealth Must Prove
When defending a DUI or drugged driving (DUID) case in Virginia—particularly one involving a blood or breath test—the outcome often hinges on the Commonwealth's ability to lay the proper foundation for admitting key evidence, especially the Certificate of Analysis. These foundational elements must be proven before the prosecution can even begin to argue guilt.
As a former prosecutor and now a criminal defense attorney serving Arlington, Stafford, Fredericksburg, Prince William, Fauquier, Fairfax, Alexandria, and Loudoun, I’ve seen how failing to establish just one of these requirements can lead to suppressed evidence—and dismissed charges.
1. Identity of the Defendant
The Commonwealth must prove—beyond a reasonable doubt—that the person on trial is the one who operated the vehicle. This is typically done through:
- In-court identification
- Bodycam or dashcam footage
- Statements made by the defendant
- Circumstantial evidence (e.g., vehicle location, ownership)
2. Venue Must Be Proper
Under Virginia Code § 19.2-244, DUI cases must be prosecuted in the city or county where the offense occurred. If venue isn't clearly established in Fairfax, Prince William, Arlington, Stafford, or elsewhere, a defense challenge may result in dismissal or transfer.
3. Officer Must Be in Uniform with Badge of Authority
Per Virginia Code § 46.2-102, the arresting officer must be in uniform and display a badge of authority. If this requirement isn’t met, the DUI stop may be unlawful—jeopardizing the Certificate of Analysis and the entire case.
4. Lawful Arrest Within 3 Hours
The Commonwealth must prove that a lawful arrest occurred within 3 hours of the alleged driving under § 18.2-268.2. Failure to meet this window could invalidate the test results.
5. Implied Consent Must Apply
Virginia’s Implied Consent Law only applies if:
- The defendant drove on a public highway, and
- A lawful arrest for DUI occurred within 3 hours
If the stop occurred on private property or the arrest lacked probable cause, implied consent may not apply—and the Certificate of Analysis may be excluded.
6. Certificate of Analysis Must Be Properly Admitted
Whether blood or breath, test results are admitted via a Certificate of Analysis. The Commonwealth must show:
Breath Test:
- Test was within 3 hours
- Conducted by a certified operator
- Using an approved, calibrated machine (e.g., Intox EC/IR II)
Blood Test:
- Drawn using a DFS-approved kit by a qualified professional
- Chain of custody documented
- Properly analyzed by DFS
7. Proper Notice and Objection Deadlines
- The Commonwealth must provide 28 days’ notice of intent to use the Certificate
- The defense has 14 days to object and request live testimony
If these deadlines are missed, the certificate may be excluded under the Confrontation Clause.
8. Chain of Custody & Sample Integrity
The prosecution must prove that the blood sample was not tampered with and that the chain of custody was strictly followed. Breaks in this chain can cast reasonable doubt and render the test results inadmissible.
9. Constitutional Protections
Every DUI case must comply with:
- Fourth Amendment – unlawful search/seizure
- Fifth Amendment – self-incrimination
- Sixth Amendment – right to confront witnesses
Violations may result in a motion to suppress the Certificate of Analysis.
Conclusion: The Foundation Is Everything
DUI convictions in Virginia depend on the prosecution's ability to establish every element—identity, venue, lawful arrest, uniformed officer, proper notice, chain of custody, and constitutional compliance.
At Dischley Law, we aggressively challenge foundational flaws in DUI prosecutions across Fairfax, Prince William, Arlington, Alexandria, Loudoun, Stafford, Fredericksburg, and Fauquier.
Call (703) 215-9337 today or contact us online at www.dischleylaw.com for a free consultation.