TX DWI and Toxicology

In Texas, police and prosecutors often rely on breathalyzer and blood test estimates to provide what they believe to be critical evidence they can use to obtain a Driving While Intoxicated (DWI) conviction. Because these toxicology tests allegedly score your level of intoxication, they can be compelling to a jury that you were operating a motor vehicle while intoxicated.

However, breath and blood tests are not always reliable and accurate. Many factors can alter the accuracy of the estimated results, and the impact of an inaccurate or unreliable toxicology test can be devastating on someone accused of DWI. If you are charged with DWI in Texas, and the evidence against you includes a blood or breathalyzer test, you need a Texas DWI Specialist Lawyer like Doug Murphy. He has the experience and expertise in excluding breath and blood test evidence in trial and also helping the Judy to see that b death and blood testing should not be provided any evidential wright due to errors in processing and/or analysis.  Doug Murphy can help you defend yourself against this potentially incriminating evidence.

Blood Alcohol Concentration

Toxicology tests are usually used to measure the amount of alcohol in a person's body. In Texas, you can be charged with DWI if your Blood Alcohol Concentration (BAC) is 0.08 percent or higher. BAC refers to the percentage of alcohol in a person's body. The higher a person's BAC, the more outward signs of intoxication present. A person with a low BAC, on the other hand, will not show signs of intoxication.

However, blood alcohol science is complicated, and individuals respond differently to alcohol depending on several highly individual factors, including their size, medications, and other factors. The specific equipment used to conduct a toxicology test can also greatly influence the outcome of the test. If you have been arrested and charged with DWI and were given a blood or breath test to determine your BAC, you need to immediately contact a defense attorney who is familiar with blood alcohol science and with the types of equipment used to test BAC.

There are many reasons why the results of a toxicology test can be wrong, including both procedural mistakes and equipment. Reasons for testing errors include:

  • Use of equipment that was improperly calibrated
  • Outdated test kits
  • Pre-existing physical conditions that could affect equipment readings
  • Contamination of samples
  • Improper storage of samples
  • Administration of tests by an untrained person
  • Errors in administering tests
  • Lab errors
  • Not following accredited forensic laboratory practices
  • Not following laboratory validation methodology and operating guidelines
  • Break in the chain of evidence
  • "Dry labbing" where results are provided but complete analysis was not done

Even if you have taken a toxicology test and the results show that you had alcohol or drugs in your system above the legal limit at the time of your breath or blood test, there are still many ways to defend yourself against a charge of DWI. You need a seasoned and experienced DWI attorney who is well-versed in knowing how to dismantle this evidence against you. Doug Murphy is an accomplished and well-regarded DWI defense lawyer who will aggressively defend you against DWI charges. Doug Murphy is one five lawyers in Texas who is Board Certified in DWI Defense.  He teaches other lawyers how to challenge this evidence.  By challenging every aspects five lawyers in Texas who is  of the evidence against you, he may be able to help you get your charges dismissed or reduced.

What Texas Law Says About Breathalyzers

When an officer pulls you over and suspects that you are driving while intoxicated (DWI), the officer must first establish reasonable suspicion that you were, in fact, driving while intoxicated. To do this, the officer may conduct a field sobriety test or use a portable breath testing device. Not all officers carry portable testing devices, though. However, neither a field sobriety test nor a portable breath test is reliable proof of intoxication, and the results from either are usually not admissible in court. They are generally enough to justify an arrest, though. After establishing reasonable suspicion, the officer must then arrest you and take you to a police station to perform an official breath test.

According to Texas law, all counties and municipalities have to follow specific guidelines concerning breath toxicology testing. The guidelines provide for breath alcohol testing requirements, administered and overseen by the Texas Department of Public Safety (TxDPS) Breath Alcohol Laboratory.

Police departments in Texas must obtain TxDPS certification for conducting breath alcohol testing, and all breathalyzer operators must also be individually certified to perform the tests. All law enforcement departments must calibrate and certify all breath testing machines per the Standardized Field Sobriety Test (SFST) standards established by the National Highway Traffic Safety Administration (NHTSA).

Many Texas police departments now use an Intoxilyzer 8000 model Breathalyzers to test BAC. Testing operators are required to have specific, up-to-date training and certification for the model of the Intoxilyzer 8000 they are using. Officers must properly calibrate and maintain equipment and must provide the supporting records and documentation of maintenance and calibration if they are asked for it.

Before testing a suspect on a Breathalyzer machine, the officer must provide you with the Texas DIC-24 DWI warning, a form that is required by law and that you must sign. The officer must also explain the testing procedures to you. If you believe your officer did not have you sign the warning form or did not explain the testing procedures, be sure to tell your attorney. If the officer neglected to follow these steps, your lawyer could use that information to help with your defense.

After getting your signature on the warning form and explaining the procedures, a certified Breathalyzer operator will perform the testing and generate a toxicology report. The operator will then conduct the test a second time. Texas law requires that the test be conducted twice so that the operator can look for any variance between the results and be certain that the equipment is working correctly.

Officers can request blood testing instead of breath testing to measure BAC, but there are also specific requirements for blood testing that must be followed.

Legal Issues with Blood Testing

Texas drivers in recent years have been subjected to forced blood tests through the “No Refusal” program. This program allows drivers who are pulled over on suspicion of DWI to be forced to submit to a blood test if they refuse to take a breathalyzer test. Judges, prosecutors, and law enforcement officers work together on the No Refusal program so that officers can get expedited search warrants that compel suspects to submit to blood tests. While the program has typically been in play only during major holiday weekends, some jurisdictions in Texas have enforced the policy year-round.

Though blood tests are often considered more precise and accurate than breath tests, there can still be issues with blood testing, such as the qualifications of the lab responsible for testing your blood sample. An experienced attorney can explore these as potential legal defenses.Depending on the factors of your case, even if your breathalyzer or blood toxicology results were well above the Texas legal limits for DWI, an attorney can identify ways to mount a defense.

“Legal Blood” vs. “Medical Blood”

There can also be flaws in the testing based on where the blood draw took place and the qualifications of the person who drew the sample. The sample itself may be called into question if it was contaminated at some point or if officers did not properly handle it after testing.

A sample of blood is drawn and tested for alcohol content when a law enforcement officers request it because they suspect a driver is intoxicated or at the request of hospital medical personnel while diagnosing and treating a patient after an accident. When law enforcement officers request the test, it is often referred to as “legal blood,” and when it is ordered by medical personnel, it is referred to as “medical blood.” The methods used to draw, prepare, track, and test legal blood can be different from those used for drawing, tracking, and preparing medical blood. An experienced attorney may be able to challenge medical blood tests in a DWI case because medical personnel sometimes do not follow specific rules set forth for conducting blood alcohol tests. Likewise, the series of labels, seals, and packing forms medical personnel use are not always the same as those required by law to be used in collecting blood for a blood alcohol test.

When blood is taken by medical personnel from someone suspected of DWI after an accident or car crash, the blood can also be contaminated if the suspect was being administered an intravenous fluid at the time the blood was drawn. The increased volume of fluid in the circulatory system can change the blood alcohol level. If the blood is drawn from the same extremity that an IV is placed in, the sample can be contaminated with the intravenous fluids.

Diseases and Medications

If a suspect suffers from certain diseases or is taking certain medications, the results of a blood alcohol test can be wrong due to the effect the disease or medication has on the suspect's body. Any drug that speeds up or slows the metabolic rate can affect blood alcohol levels, including medicines that are as common as oral contraceptives.

Likewise, any disease that affects the liver, such as hepatitis, can alter the results of blood alcohol test, as can any condition that causes water retention, such as heart disease, many forms of high blood pressure, or diabetes.

Even though breath and blood alcohol tests can seem like damning evidence against you, there are many ways the results of these tests can be called into question. It's very important that you contact an experienced, knowledgeable DWI Specialist attorney like Doug Murphy to help you, and that you share specific information about your health and the process you experienced before, during, and after you were tested. Doug Murphy has a well-earned reputation as one of the best DWI lawyers in the nation in due to his track record of saving countless clients through cases by excluding or limiting breath and blood toxicology evidence, and he knows how to help you, too.

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If you are facing DWI or other criminal charges in Texas, contact our office today to discuss your case, so we can begin working on your defense. Please provide only your personal email and cell phone number so that we can immediately and confidentially communicate with you.