Blood Tests After a Virginia DUI Arrest and How the Results Can Be Challenged
A blood test can become one of the most important pieces of evidence in a Virginia DUI prosecution. Unlike a roadside observation or field sobriety exercise, a laboratory report gives the prosecution a number that can appear precise and difficult to dispute. Blood testing is also frequently used when police suspect drug impairment, when a breath test is unavailable, or when circumstances surrounding an accident lead officers to seek additional chemical evidence.
The laboratory result is only part of the story. How the blood was obtained, who collected it, how the vials were sealed and handled, and what happened once the sample reached the laboratory can all affect the strength of the evidence. After a DUI arrest involving a blood draw, an experienced Virginia DUI defense attorney can examine the process behind the reported result and identify issues that deserve closer scrutiny.
When Virginia DUI Investigations Lead to a Blood Test
Virginia’s implied-consent statute governs much of the chemical testing that follows a DUI arrest. Under Virginia Code § 18.2-268.2, a person who operates a motor vehicle on a Virginia highway is deemed to have consented to blood, breath, or both forms of testing under qualifying circumstances when arrested within three hours of the alleged offense. For an alcohol-related DUI, breath testing ordinarily comes first, with blood testing available under circumstances specified by the statute.
Blood testing plays an especially important role in suspected drug-impaired driving cases. A breath machine cannot identify prescription medications, illegal drugs, or other substances that might be present in a driver’s system. The Virginia Department of Forensic Science receives blood samples submitted during DUI and drug-impaired-driving investigations and analyzes them for alcohol and drugs.
The type of substance matters because Virginia DUI law treats different forms of intoxication differently. Virginia Code § 18.2-266 establishes a blood-alcohol threshold of 0.08 percent and specific blood-concentration thresholds for several named drugs, including cocaine, methamphetamine, PCP, and MDMA. For many other drugs, however, the presence of a substance does not come with the same statutory numerical threshold.
How the Blood Draw Was Performed Can Affect the Evidence
A DUI blood sample starts with the person who draws it. Virginia Code § 18.2-268.5 limits who is authorized to withdraw blood for alcohol or drug testing and also addresses the procedures and materials used during the collection process. Physicians, certain nurses, phlebotomists, and other specifically authorized personnel are among those permitted to perform the draw. The statute also identifies acceptable cleansing agents and requires appropriate sterile equipment.
Those requirements give a defense attorney a concrete record to examine. The identity and qualifications of the person who performed the draw, the time recorded for collection, and the procedures reflected in the accompanying documentation can be compared against what Virginia law requires.
A discrepancy does not automatically invalidate every blood test. Its significance depends on what occurred and how that problem affects admissibility, reliability, or the weight a court gives the evidence. A meaningful defense therefore looks beyond the final laboratory number and reconstructs the collection process that produced the sample.
What Happens to the Sample After the Blood Is Drawn
Once blood leaves a person’s body, preserving the identity and integrity of the specimen becomes critical. Virginia Code § 18.2-268.6 provides detailed requirements for the vials and their transmission. The blood goes into containers provided or approved by the Department of Forensic Science, the vials are sealed, and withdrawal certificates contain identifying information including the accused’s name, the person who drew the blood, and the date and time of collection. The sealed container is then placed in the custody of the arresting or accompanying officer for delivery to the Department.
That paper trail can expose problems that the reported concentration alone cannot show. Missing identifying information, an unexplained break in possession, questions about a seal, or inconsistencies between the withdrawal documentation and laboratory records deserve attention because the prosecution is relying on a particular specimen as the defendant’s blood.
Virginia Code § 18.2-268.7 also requires the Department’s certificate of analysis to contain information concerning receipt and examination of the sample, the condition of the seal, and the blood’s reported alcohol or drug content. The documentation surrounding the specimen can therefore become an important part of evaluating the prosecution’s evidence rather than a procedural formality sitting behind the laboratory report.
Why a Laboratory Number Does Not End the Analysis
Forensic blood testing involves scientific procedures, instruments, calibration, quality controls, interpretation, and reporting. The Virginia Department of Forensic Science maintains detailed toxicology procedures for this work. Its training materials describe the use of headspace gas chromatography for blood-alcohol analysis, along with specimen preparation, calibration, internal standards, and examination of chromatograms.
A defense review can reach beneath the certificate of analysis to the laboratory material supporting that result. Depending on the case, that can include analytical data, calibration information, quality-control records, chromatograms, testing methodology, and documentation concerning any deviation from established procedures.
This becomes particularly significant when the reported concentration is close to a statutory threshold or when something in the underlying laboratory material does not match the simplicity of the number presented in court. Forensic testing is designed to produce reliable results, but the reliability of a particular result still depends on what occurred in that particular analysis.
Drug Detection and Driver Impairment Are Different Questions
Drug-related DUI blood tests create another issue. Detecting a substance in blood establishes that the laboratory identified that substance at the time reflected by the specimen. For many drugs, it does not by itself supply a statutory answer to how impaired the driver was.
The Virginia Department of Forensic Science notes that, outside the substances for which Virginia has established numerical statutory limits, expert toxicology testimony is often necessary to address how a drug or combination of drugs affects human performance and driving behavior. A reported result involving a prescription medication, metabolite, or other drug therefore has to be considered in the context of the substance involved and the prosecution’s theory of impairment.
Other evidence from the traffic stop can become important here. The driver’s behavior, physical symptoms, statements, driving pattern, medical circumstances, and observations made by officers can be compared with what the toxicology evidence actually establishes. A laboratory report identifying a drug does not answer every question about how that drug affected the driver at the relevant time.
A Blood Test Challenge Begins With the Records Behind the Result
The certificate handed to the court is the end product of a much longer process. A meaningful review can trace that process backward from the reported concentration to the laboratory analysis, receipt of the sealed specimen, officer custody, collection documentation, and original blood draw.
That review also helps separate a genuine scientific or procedural problem from a technical discrepancy that has little effect on the prosecution. DUI defense is strongest when the challenge is tied to the actual evidence rather than a generalized attack on blood testing.
When chemical evidence is likely to play a major role in the prosecution, guidance from a knowledgeable Virginia DUI defense lawyer can help identify what happened between the initial blood draw and the final laboratory report and whether the records support the result the Commonwealth intends to use.
Speak with Our Virginia DUI Defense Attorneys
If you were arrested for DUI and blood was taken for alcohol or drug testing, the laboratory report can have serious consequences for the criminal case and your ability to drive. The result deserves to be examined alongside the collection records, handling documentation, laboratory data, and circumstances surrounding the arrest.
Contact Simms Showers LLP today to speak with an experienced Virginia DUI defense attorney and learn how we can help protect your rights after a DUI arrest. We offer a free phone consultation for criminal defense cases.
This memorandum is provided for general information purposes only and is not a substitute for legal advice particular to your situation. No recipients of this memo should act or refrain from acting solely on the basis of this memorandum without seeking professional legal counsel. Simms Showers LLP expressly disclaims all liability relating to actions taken or not taken based solely on the content of this memorandum.
Sources:
- Virginia Code § 18.2-266, Driving Motor Vehicle, Engine, Etc., While Intoxicated
law.lis.virginia.gov/vacode/title18.2/chapter7/section18.2-266/ - Virginia Code § 18.2-268.2, Implied Consent to Post-Arrest Testing
law.lis.virginia.gov/vacode/title18.2/chapter7/section18.2-268.2/ - Virginia Code § 18.2-268.5, Qualifications and Procedure for Taking Blood Samples
law.lis.virginia.gov/vacode/title18.2/chapter7/section18.2-268.5/ - Virginia Code § 18.2-268.6, Transmission of Blood Samples
law.lis.virginia.gov/vacode/title18.2/chapter7/section18.2-268.6/ - Virginia Code § 18.2-268.7, Transmission of Blood Test Samples; Use as Evidence
law.lis.virginia.gov/vacode/title18.2/chapter7/section18.2-268.7/ - Virginia Department of Forensic Science — Toxicology
dfs.virginia.gov/laboratory-forensic-services/toxicology/ - Virginia Department of Forensic Science — Toxicology Manuals
dfs.virginia.gov/laboratory-forensic-services/toxicology/toxicology-manuals/
