When a DWI blood sample is stored incorrectly in Texas, questions may arise about the reliability of the test results, the integrity of the evidence, and whether the sample accurately reflects a driver’s blood alcohol concentration. Improper storage does not automatically cause a DWI case to be dismissed, but it may create issues involving contamination, degradation, chain of custody, or laboratory procedures that can affect how the evidence is evaluated.
San Antonio is one of the largest cities in Texas and serves as a major center for business, tourism, and transportation. The city is connected by several heavily traveled highways and experiences significant daily traffic from residents and visitors alike.
Because of the large number of vehicles on local roads, law enforcement agencies regularly investigate traffic offenses, including allegations of driving while intoxicated. Individuals working with a San Antonio DWI lawyer often want to understand whether mistakes involving blood evidence could affect the outcome of a DWI case.
Why Blood Sample Storage Matters
Blood samples are biological evidence that require proper handling and preservation. After a sample is collected, it is typically labeled, stored, transported, and tested according to established procedures. These procedures are intended to help ensure that the sample remains in the same condition as when it was collected and that the test results accurately reflect the evidence obtained during the investigation.
If mistakes occur during storage, concerns may arise regarding whether the sample was altered, contaminated, or otherwise affected before testing.
Understanding Chain of Custody
One important issue in DWI cases is the chain of custody. Chain of custody refers to the documented handling of evidence from the moment it is collected until it is presented in court. This documentation helps establish who handled the sample, where it was stored, and whether it remained secure throughout the process.
When a blood sample is stored incorrectly, or documentation is incomplete, questions may arise about whether the evidence was properly preserved and whether the sample tested by the laboratory is the same sample collected from the driver.
Potential Problems Caused by Improper Storage
Several issues can result from improper storage practices. For example, a sample that is exposed to inappropriate temperatures may deteriorate over time. Labeling errors can create confusion regarding the identity of the sample. Contamination may occur if proper procedures are not followed during handling or storage.
These concerns do not automatically prove that the blood test is inaccurate, but they may become relevant when evaluating the reliability of the evidence.
Laboratory Testing and Evidence Reliability
Blood alcohol testing involves scientific procedures designed to measure the concentration of alcohol or other substances in a person’s blood. If questions arise regarding how a sample was stored, attorneys may review laboratory records, storage logs, testing procedures, and quality-control measures.
Experts may also examine whether the condition of the sample could have affected the test results. Because blood evidence often plays a significant role in a DWI prosecution, both sides may closely examine how the evidence was handled.
Improper Storage Does Not Automatically Dismiss a Case
Many people assume that any mistake involving evidence automatically results in the dismissal of criminal charges. In reality, courts often evaluate the specific facts surrounding the storage issue. A minor documentation error may be treated differently than evidence suggesting contamination or mishandling that affects the reliability of the test results.
The significance of the storage problem generally depends on the nature of the mistake and whether it raises legitimate concerns about the accuracy of the evidence.
Texas Law Governing Blood Specimens
Texas Transportation Code § 724.017 contains important requirements regarding the taking of blood specimens in DWI investigations. The statute addresses who may draw a blood sample and establishes certain procedural requirements related to the collection of evidence.
Compliance with these requirements can become important when evaluating the admissibility and reliability of blood-test evidence in court.
Why Early Investigation Matters
Evidence-related issues are often easier to evaluate when records are preserved and reviewed promptly. Attorneys may examine collection procedures, storage conditions, laboratory reports, chain-of-custody documentation, and witness statements to better understand how the sample was handled.
Early review can help identify potential issues before important evidence becomes unavailable. Every DWI case is unique, and the impact of a storage issue depends on the specific circumstances involved.
Key Takeaways
- Improperly stored blood samples can raise questions about evidence reliability.
- Chain-of-custody documentation helps establish how evidence was handled.
- Storage errors may involve contamination, degradation, or labeling concerns.
- Blood-test evidence is often closely examined in DWI cases.
- Improper storage does not automatically result in dismissal of charges.
- Texas Transportation Code § 724.017 establishes requirements for blood specimen collection.
- The significance of a storage issue depends on the facts and evidence in the particular case.
