If you've been charged with DUI in Tennessee — especially a serious charge like vehicular homicide — you may assume that the Blood Alcohol Concentration (BAC) test result is airtight evidence. After all, it came from a state crime lab. A trained professional drew your blood. The Tennessee Bureau of Investigation analyzed it.
But what if the container your blood was stored in had expired?
That's not a hypothetical. The bigger concern, TBI encouraged law enforcement to use expired blood tubes.
The Case: Expired Vacutainers and a BAC Test Under Fire
In a recent vehicular homicide case, law enforcement drew blood at the scene and submitted two vials to the TBI Crime Lab for BAC testing. Through discovery, I obtained photos of the actual vials used — grey-capped BD Vacutainer tubes, bearing an expiration date of November 30, 2018.
The blood was drawn in April 2022.
The manufacturer, Becton Dickinson, is explicit in its product instructions: do not use tubes after their expiration date. The hourglass "use by" symbol on the label says it plainly. The Tennessee Bureau of Investigation blatantly disregarded what the manufacturer has stated.
Why This Matters Legally
1. Unreliability Under Tennessee Rules of Evidence 702 and 703
BAC testing is scientific evidence, and Tennessee courts require that scientific evidence meet reliability standards before it can go to a jury. The methodology used to collect the blood — storing it in recalled, expired containers against the manufacturer's explicit instructions — calls into question whether the results reflect actual BAC levels or contamination and interference from degraded tube components.
2. Failure of Authentication Under T.R.E. 901
Before evidence can be admitted, the State must establish its identity and integrity. When both vials are stored in expired, recalled containers, there is no baseline to determine how — or whether — the samples were affected. Without an unexpired comparator, the integrity of the evidence simply cannot be verified.
3. Due Process Violation
The right to a fair trial is guaranteed by the Fourteenth Amendment to the U.S. Constitution and Article 1, Section 8 of the Tennessee Constitution. When the State collects and stores scientific evidence in a manner that renders it unreliable — contrary to accepted standards — it violates a defendant's due process rights. Just as a one-person lineup taints an eyewitness identification, using recalled and expired collection devices taints the blood evidence itself.
The Takeaway for Anyone Charged with DUI in Tennessee
Most people facing DUI or DUI-related charges never think to ask about the equipment used to collect their blood. They assume the State followed proper procedure. In my experience, that assumption is often wrong — and the consequences of not challenging it can be devastating.
Expired tubes. Improper storage. Chain of custody gaps. Calibration records for testing instruments. Quality control logs from the crime lab. These are not technicalities — they are the building blocks of a legitimate defense.
A BAC result is only as reliable as the process that produced it. My job is to scrutinize every step of that process.
Facing DUI or DUI-Related Charges in Tennessee?
If you or a loved one has been charged with DUI, aggravated vehicular assault, or vehicular homicide involving an alleged blood alcohol result, don't take the State's evidence at face value. Your life could depend on it.