Knowledge Vault

DWI Defense

The science and law behind every DWI — blood and breath testing, the NHTSA field sobriety tests, and retrograde extrapolation. Written by attorneys who teach this material, including the first in Texas to pass the Forensic Sobriety Assessment Certification exam.

DWI Defense

Latest in DWI Defense

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Ask Deandra: What Is an ALR Hearing and Do I Need One?

By Deandra Grant, J.D., M.S. (Pharmaceutical Science), ACS-CHAL Forensic Lawyer-Scientist The question: What is an ALR hearing, and do I need one? The short answer: An ALR hearing is an administrative proceeding…

May 11, 2026 Read
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Ask Deandra: Can I Refuse a Breath Test in Texas?

By Deandra Grant, J.D., M.S. (Pharmaceutical Science), ACS-CHAL Forensic Lawyer-Scientist The question: Can I refuse a breath test in Texas? The short answer: Yes. You can legally refuse a breath test in…

Apr 27, 2026 Read
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Ask Deandra: Can a DWI Blood Test Be Wrong?

By Deandra Grant, J.D., M.S. (Pharmaceutical Science), ACS-CHAL Forensic Lawyer-Scientist The question: Can a DWI blood test be wrong? The short answer: Yes. Blood alcohol and blood drug testing is presented to…

Apr 27, 2026 Read
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Ask Deandra: How Accurate Is the Breathalyzer in Texas?

By Deandra Grant, J.D., M.S. (Pharmaceutical Science), ACS-CHAL Forensic Lawyer-Scientist The question: How accurate is the breathalyzer in Texas? The short answer: Less accurate than the prosecution will tell the jury. Texas…

Apr 24, 2026 Read