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Houston Attorney for Laboratory Errors in DWI Blood Tests

Common Lab Mistakes in Texas DWI Cases

Getting pulled over when a police officer suspects you are driving while intoxicated (DWI) can be a terrifying experience. If you've taken the roadside sobriety tests and move on to the blood sample phase, it becomes even scarier. Maybe you refuse and the officer must call for a warrant, or maybe you consent, but the fact remains that once you have provided a blood sample to the state, you wait for the results and must abide by what the forensic laboratory concludes, right?

Not exactly.

If the results of the blood test show a blood-alcohol concentration (BAC) that you believe couldn't possibly be correct—that your actual BAC should have been lower, perhaps even under the legal limit—you do have some recourse, but you'll have to move quickly. With an experienced and Board Certified DWI attorney by your side, you can effectively challenge blood test results based on several arguments, including potential forensic laboratory errors.

Board Certified DWI defense lawyer Doug Murphy has successfully challenged DWI charges throughout his legal career with many arguments resting on the simple theory that people do make mistakes. "People" include those who work in forensic laboratories and handle blood tests, and there are several ways an experienced DWI attorney can attack the validity of those results.

If you've been charged with a DWI, contact Doug Murphy today to discuss the specifics of your case and get moving on your DWI defense.

Texas DWI Law

Under Texas law, a person may be arrested and charged with DWI if they have a BAC of .08 or higher. By definition, intoxication in Texas is "not having the normal use of mental or physical faculties by reason of the introduction of alcohol, a controlled substance, a drug, a dangerous drug, a combination of two or more of those substances, or any other substance into the body; OR (b) having an alcohol concentration of .08 or more."

To prove that you should be convicted of DWI, the state must show beyond a reasonable doubt that you were operating a motor vehicle in a public place while intoxicated. If the state can show you had a BAC of .08 percent or higher either through a blood or breath test, you will be found to have been intoxicated. Alternately, the state would have to produce evidence, likely through witnesses, that you lacked normal use of your mental or physical faculties.

For a first DWI offense, a driver faces from 3 to 180 days in jail, a fine of up to $2,000, and loss of driver's license for up to a year. A second offense carries one month to a year in jail, a fine of up to $4,000, and loss of driver's license for up to two years. A third offense could lead to 2 to 10 years in prison, a $10,000 fine, and loss of driver's license for up to two years.

In addition, after two or more DWI convictions in five years, the driver must install an ignition interlock device that prevents the vehicle from starting if the driver has been drinking.

Starting in the fall of 2019, Texas added mandatory fines after doing away with surcharges in addition to the potential consequences listed above.

  • First DWI in a 36-month period: $3,000
  • Subsequent DWI in a 36-month period: $4,500
  • BAC of .15 or greater: $6,000

In addition to the potential for serving jail time and paying hefty fines, a DWI conviction can reach into many aspects of your life, including current and future employment opportunities depending on your job. Because the potential consequences are so severe in the case of a DWI conviction, you should get working on your defense as soon as possible.

DWI Law Concerning Blood Tests in Texas

In Texas, if a police officer suspects you may be driving while intoxicated, they may ask you to take a blood test. The Texas Transportation Code Section 724.012 provides that an officer may request a breath or blood test based on "reasonable grounds to believe the person" was "intoxicated [while] operating a motor vehicle in a public place."

In some instances, a blood test is mandatory, such as when there has been an accident in which there was serious injury or death; the suspected driver had a child passenger in the vehicle; or the suspected driver has already been convicted twice of DWI, DWI with child passenger, intoxication assault, or intoxication manslaughter. These statutorily mandated blood draw situations are no longer legally authorized after the U.S. Supreme Court ruling in Missouri v. McNeely.

Whether you voluntarily consented to a blood draw or whether it was required based on the circumstances of your case, you still have defense avenues to pursue to challenge your arrest. For instance, if your blood was drawn without a search warrant after you refused a blood test, you may have solid grounds to keep the entire test out of the court record.

As you can see, having an experienced DWI attorney to represent your interests as early in the process as possible is crucial to developing your best defense possible.

DWI Blood Test Laboratory Errors

Just because a laboratory finds a BAC that violates state DWI laws doesn't mean your case is open and shut.

In 2014, a Bexar County laboratory—and hundreds of DWI cases—came under scrutiny when it was revealed that a forensic laboratory employee had grossly mishandled blood samples, mislabeling approximately 300 of them.

This type of failure to follow laboratory protocol can allow an experienced DWI attorney to challenge the results of a blood-alcohol test.

Potential DWI laboratory errors can begin even before that, however. Laboratories may fail to properly collect and/or store blood samples, which can render their results faulty.

If your sample was not drawn promptly, or if it was taken during a time when your BAC was spiking, the sample may not have been an accurate reflection of your BAC at the time you were operating a motor vehicle. Drawing the blood incorrectly can also compromise the test's accuracy through potential contamination, so the procedure as well as the person conducting it must be analyzed carefully.

Moving to potential problems with storage, there are several ways a laboratory can fail to handle and store blood samples correctly:

  • Mislabeling and other paperwork errors
  • Contamination of sample during storage procedures
  • Intermingling samples
  • Fermentation of samples
  • Interchanging samples

Another possible problem is with the equipment that tests the blood samples. In 2013, a forensic laboratory in California revealed that thousands of blood test results were inaccurate because one of the two machines the lab used was calibrated off by .003 percentage points. Standard safeguard procedures detect errors of .004 percent or more, which meant that one of the two machines—the lab averaged the results of two machines to account for irregularities—wasn't producing accurate readings.

As a result of the investigation into the forensic laboratory's machines, approximately 200 DWI cases had inaccurate BAC results attached to them. Although .01 percent difference may not seem like much, for those defendants whose BAC moved above the legal limit because of the faulty results, that percentage was huge. The same holds true for anyone whose BAC pushed them into a penalty phase that included higher fines, loss of driver's license, and even increased jail time.

In Texas, blood-alcohol concentration is determined through the use of a relatively complex process using a machine called a gas chromatograph. Generally, a blood vial is heated, and the alcohol in the blood evaporates, theoretically filling the rest of the vial with air that represents the proportionate amount of alcohol in the blood. The air is sampled and transferred to a "column," where it is burned. The reaction is measured, and a chromatogram report is produced. This report is complicated and difficult to understand, requiring an experienced DWI lawyer to analyze and investigate results.

These machines must be working properly and operated correctly for this complex process to result in an accurate BAC reading. An experienced DWI attorney will consider the equipment maintenance, inspection, and calibration records, along with the relative experience of the technicians conducting the blood testing procedures. As human error can play such a critical role in the reliability of BAC test results, the qualifications of all of the people who handled the blood sample in question must be investigated.

Get Advice From a Board Certified Harris County DWI Lawyer

If you have been charged with a DWI offense, there's no time to waste in getting an experienced, Board Certified DWI lawyer on your side right now. Attorney Doug Murphy has many years of experience in defending those accused of DWI—and he gets results. Your freedom and livelihood could be at risk with a DWI charge, so get in touch with the Doug Murphy Law Firm, P.C. today by calling our office at 713-229-8333.

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