Facing DWI charges with a blood draw warrant in Fort Worth? The validity of that warrant and the procedures used to draw and test your blood can be challenged. At Norris Legal Group, we protect your Fourth Amendment rights and fight to suppress illegally obtained blood evidence.

Call (817) 859-8985 for a Free Case Evaluation

How Blood Draw Warrants Work in Texas DWI Cases

When you’re arrested for DWI in Texas, police may seek a warrant to draw your blood and test your BAC. Following the U.S. Supreme Court’s decision in Missouri v. McNeely (2013), law enforcement generally must obtain a search warrant before forcibly taking your blood.

During Tarrant County’s no-refusal periods, prosecutors and judges are on-call to approve warrants within minutes when drivers refuse testing.

Challenging Blood Draw Evidence

Graham Norris examines every aspect of your case to identify violations of your rights. As he explains: “They’ve got to show that that test was taken in a way that comports with the law so that they had a legal right to take it, that they didn’t violate any of your rights when they took it, and that it was done according to the science.”

Warrant Validity Issues

• Lack of probable cause in the warrant application
• False or misleading statements by officers
• Procedural defects in warrant execution
• Timing and staleness issues

Blood Draw Procedure Violations

• Unqualified personnel performing the draw
• Improper sanitation or sterile technique
• Chain of custody problems
• Storage and preservation failures

Testing Reliability Problems

• Lab accreditation and certification issues
• Technician qualification defects
• Contamination or fermentation
• Equipment calibration problems

According to the National Highway Traffic Safety Administration (NHTSA), breath and blood tests are not always accurate. Your lawyer will ensure the tests were done correctly and challenge any errors. Problems with calibration, maintenance, or administration can lead to inaccurate results, which can be contested in court.

The Blood Test Timeline Problem

Even when blood tests show elevated BAC, the prosecution must prove you were intoxicated while driving, not hours later when your blood was drawn.

Graham Norris explains: “That score was taken after the fact. And what they have to prove in court is that you were driving while intoxicated. That means that they have to prove you were intoxicated while you were operating the vehicle.”

We challenge retrograde extrapolation calculations and demonstrate that your BAC at the time of driving may have been below the legal limit.

Critical Timeline: Protect Your Rights

Within 15 Days: Request Your ALR Hearing

Graham Norris emphasizes the importance of this deadline: “What we always do in these cases is we subpoena the officer, the arresting officer, to appear at that license hearing. And obviously, the goal is to save somebody’s driver’s license. But beyond just that, it gives us the opportunity to cross examine that police officer and to sometimes use that testimony in the criminal case.”

If you’ve been arrested for DWI, you have just 15 days to request an ALR hearing — missing this deadline means an automatic license suspension. Don’t wait.

Real Case Results

Prescription Medication Case Dismissed

Our client was charged with DWI when prescription drugs and heat stroke caused confusion. Blood tests showed prescription medication in her system. We gathered expert medical testimony and secured a complete dismissal on the eve of trial.

Graham describes the outcome: “She was not in her right mind and shouldn’t have been driving. But that was not her decision. Right. And that’s the difference where there’s not there wasn’t criminal culpability there so we got that case dismissed.”

Why Choose Norris Legal Group

Former Prosecutor Insight: Graham Norris’s background as a Tarrant County prosecutor gives him unique knowledge of how the state builds DWI cases and where weaknesses exist.

Meticulous Investigation: We check every detail. “We’re really checking officers’ work because there is a certain procedure with field sobriety tests and with any type of specimen so either a breath specimen or a blood specimen that they have to go through. And if they violate or break any of the rules or do it incorrectly, they can either result in the test [being inadmissible].” Learn more about how to fight a DWI in Texas.

Dignity and Respect: “We believe that every person no matter if they’ve made a mistake or not, deserves to be treated with dignity and respect. And because of that, what we’ve learned is that really good people sometimes make mistakes.”

Proven Results: Over 400 case dismissals and 60+ grand jury “no-bills” across 3,600+ criminal cases.

Blood Test Results Don’t Guarantee Conviction

Many clients believe their case is hopeless because of blood test results. Graham Norris disagrees: “If you have a specimen that shows that at the time that they drew that specimen, it was above point [0.08]. That’s a powerful piece of evidence for them to use. However, their job is not done.”

The prosecution must prove they had legal authority to take your blood, followed proper procedures, obtained reliable results, and that you were intoxicated while driving — not just when tested hours later. Texas blood draw procedures are governed by standards set by the Texas Department of State Health Services, and any deviation from those standards can be grounds to challenge your results.

For a broader look at your options if you’ve been charged, see our guide on getting a DWI dismissed in Texas.

Get Your Free Case Evaluation

Don’t let blood draw evidence push you into accepting an unfavorable plea. We have the knowledge and track record to challenge blood draw warrants and fight for your rights.

Contact us now for a free case evaluation, or call (817) 859-8985.

Serving Fort Worth, Arlington, Bedford, Mansfield, Euless, Hurst, Keller, Southlake, and all of Tarrant County.