Blood and Breath BAC Tests Are Unreliable

Our Austin, TX DWI defense lawyers explain why results are weak evidence

One of the potentially critical components in a DWI case are Blood Alcohol Concentration (BAC) test results. Some prosecutors and police build cases around allegedly failed BAC tests. However, at Botsford & Roark, we know that BAC test results are frequently wrong and the chances for samples and testing to be corrupted are numerous. Our Austin DWI defense lawyers excel at demonstrating this to judges and juries.

Since 2007, Botsford & Roark has used our knowledge, connections, and legal skill to protect the rights and freedom of people accused of DWI in Central Texas. Our methods are time-tested and true. We know how the system works here and how to make it work for you. If you have been charged with DWI, contact us for a free and confidential case evaluation.

Types of BAC tests

BAC testing is often used as a fundamental tool by police to determine whether an individual was driving while intoxicated. BAC measures the concentration of alcohol in a person's bloodstream. In general, the legal limit for drivers is 0.08% BAC. However, for commercial drivers, it's 0.04%, and for individuals under 21, any detectable amount of alcohol can lead to DWI or DUI charge in Texas.

There are two primary methods for measuring BAC: blood tests and breath tests. Urine tests for BAC were once standard, but, as the least accurate form of chemical testing, law enforcement rarely use them anymore. Each type of test has its inherent weaknesses that our Austin DWI defense lawyers can exploit to your advantage.

Breath tests. When you're pulled over on suspicion of DWI, the officer may request that you blow into a Breathalyzer device. The device estimates your BAC by measuring the alcohol in your breath. While breath tests are convenient and provide rapid results, they frequently produce unreliable results. Factors like medical conditions, calibration errors, or improper administration can lead to falsely high readings. These issues can become crucial points of contention in your DWI defense.
Blood tests. Blood tests are considered by some to be one of the most accurate methods for determining BAC. When you're arrested for DWI in Texas, law enforcement may request a blood sample to analyze your BAC. Blood tests are typically conducted in controlled environments, like a medical facility or law enforcement agency, by trained professionals. The collected sample is then sent to a laboratory for analysis. However, blood tests are not without potential issues. Mishandling of samples or errors in the chain of custody can lead to contested results.

Challenging BAC results

A BAC over the legal limit does not necessarily mean a driver will be convicted of DWI in Texas. Challenging BAC test results is a common strategy in DWI defense. At Botsford & Roark, our determined DWI defense lawyers recognize that these tests are not infallible. We may:

Question sample handling
Check equipment records
Examine operator mistakes

If you or your child is navigating a DWI charge, we can help. Based in Austin, TX, you can contact our firm for a free case evaluation. We can answer questions and explain your legal options. With decades of experience, you can feel confident that Botsford & Roark is protecting your freedom, reputation, and future.