DWI Blood Test

To determine a person’s blood alcohol concentration, law enforcement use various types of chemical testing including blood analysis. Usually, law enforcement will default to a breath test if they suspect a driver is under the influence of alcohol. Officers tend to turn to blood testing if they suspect alleged drug use is the cause for impairment. That is because you cannot determine if a person has used drugs from a breath sample.

DWI blood tests, while rooted in science, can sometimes yield incorrect and/or skewed results. These tests must be conducted by a professional because there’s a very high margin for error. Various factors could influence the results including contaminated samples, breaks in chain of custody, poorly stored samples, or failing to sterilize necessary medical equipment. For these reasons and more, we highly encourage you to challenge your blood test results with an experienced DWI defense lawyer in Cameron County, Texas.

Cameron County Lawyer for DWI Blood Tests

Blood analysis may be the most accurate form of DWI chemical testing, but that doesn’t mean it’s without fault. Many outside and internal factors could influence blood test results and ultimately lead to driving while intoxicated (DWI) charges. If you wish to challenge your DWI blood test results, contact the experienced Brownsville drunk driving defense lawyers at The Gracia Law Firm, P.C. .

Our criminal defense attorneys have helped hundreds of clients contest their blood test results. We will work tirelessly to ensure you receive the best possible result for your case. Call The Gracia Law Firm, P.C. to set up your first consultation free of charge.

The Gracia Law Firm, P.C. accepts clients throughout the greater Brownsville and Cameron County area including La Feria, Olmito, Palm Valley, Port Isabel, Rio Hondo, San Benito, and Harlingen. We also represent clients in Willacy County and Hidalgo County, Texas.

Information Center:


Back to top

What Do Blood Tests Test For?

Law enforcement agencies utilize chemical testing to determine a person’s blood alcohol concentration. The majority of the time officers will ask suspected drunk drivers to submit to a breathalyzer test. They typically will only ask drivers to submit a blood sample if they have reasonable suspicion they are under the influence of drugs. That’s because breath samples are much less likely to pick up on alleged drug use and are designed to detect ethanol.

Law enforcement will defer to blood analysis if they are unable to get a BAC reading and suspect drug use. That is because blood analysis is the most accurate of the three tests. It can detect all types of drugs and how much of the substance is in your system. The analysis of the results must also be read by a lab or health care technician and are usually conducted in a hospital setting. If you have a BAC of .08 or higher, officers can arrest you for DWI.


Back to top

DUI Blood Test Errors

Out of all three chemical tests, blood analysis is the most reliable and accurate. Blood tests can detect drugs in a person’s system and how long the drug has been in their system. Despite the accuracy of blood analysis, the results are still susceptible to human error. Outside and internal factors could influence blood analysis readings including unsanitary testing conditions or failure to sterilize the medical equipment before and after testing.

Listed below are some additional issues associated with DWI blood testing.

  • Fail to take two samples
  • Use an outdated testing kit
  • Samples being mislabeled
  • Conditions for testing were unsanitary
  • The sample was too decomposed to test
  • There was a break in chain of custody, and it induced confusion
  • The technicians at the hospital or lab were inadequately trained
  • The sample was taken by an unauthorized person
  • Inability to convert serum or plasma blood
  • The sample was contaminated by alcohol during sterilization
  • The second blood test gave very different results
  • The sample wasn’t stored properly

Back to top

How to Beat a DUI Blood Test

The best way to “beat” a DWI blood test is to refuse one altogether. Despite implied consent laws, you are within your right to refuse DWI blood analysis. Refusing a blood test will deny the prosecution any scientific evidence of your intoxication. They will instead have to rely on dash cam footage, and subjective testimony from officers and eyewitnesses.

Refusing testing is a great way to handicap the prosecution in a DWI case. However, it does come with some consequences. You will automatically receive an administrative license suspension for up to 180 days and a second refusal will result in a one-year license suspension.

While a license suspension is a hassle to deal with, it’s much easier to resolve than a DWI conviction. You can file a request for an administrative license revocation hearing within 15 days of your refusal to challenge the suspension. At the hearing, you and your attorney can present evidence as to why the suspension isn’t necessary and even advocate for a restricted license if you qualify.


Back to top

Additional Resources

ALR Program in Texas– Visit the official website of the Texas Department of Public Safety (DPS) to learn more about their administrative license revocation (ALR) program for DWI offenders and those who refused testing. Access the site to look at the suspension terms, how ALR hearings work, and how to get an occupational license.

Drunk Driving Laws in Texas– Visit the official website of the Texas Penal Code to learn more about their DWI laws (driving while intoxicated). Access the site to learn the penalties for DWI and aggravated DWI, admissible defenses, and DWI chemical test procedures.


Back to top

DWI Blood Test Brownsville Lawyer | DUI Blood Test Accuracy

If you or someone you know has been charged with DWI using blood analysis, challenge the results today with The Gracia Law Firm, P.C. The Cameron County DUI lawyers at The Gracia Law Firm, P.C. have been assisting clients accused of DWI using faulty blood results for years. Our extensive scientific understanding of DWI chemical tests as well as our legal experience can help you fight the results, and ultimately beat your DWI charges.

Schedule your first consultation today with The Gracia Law Firm, P.C. by calling our office at 956-504-2211. The Gracia Law Firm, P.C. accepts clients in Cameron County and other counties including Hidalgo County and Willacy County, Texas.


Back to top