TRIAL TESTED & PROVEN

HOUSTON DWI ATTORNEY

We're Obsessed With Winning: Let Us Fight For You

Were you arrested and charged with DWI? If so, you have some hard deadlines approaching if you want to save your driver’s license and protect your freedom. 

Don’t risk going it alone. Work with a team of experienced DWI lawyers who know how to beat DWI charges — both in and out of court. We’ve fought and won more than 100 Not Guilty Verdicts and gotten thousands of cases dismissed.

Get your case off to the right start: Thiessen Law Firm offers a free case evaluation, and we are available 24 hours a day, 7 days a week to protect your freedom and ease your concerns.

How We Win DWI Cases

A lot of lawyers promise to fight, but few truly know how to win. These are just some of the strategies Thiessen Law Firm have successfully deploy to beat DWI charges.

  • Debunking breath tests: Breath tests are built around junk technology and can often be wrong. As a Board Certified DWI Defense Expert, Mark Thiessen knows how to effectively beat bad evidence.

  • Fighting and beating blood tests: As a lawyer-scientist, Mark Thiessen is one of the few DWI lawyers who can effectively use science to challenge and beat the results of a blood test.

  • Battling bad police work: When the police don’t play by the rules, we use case law to take them to task.

  • Earning the respect of the court: At trial, the power of respect is everything. Over his career, Mark Thiessen has built strong relationships with the judges and prosecutors who try DWI cases in Houston.

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What's My First Step?

Give as little information as possible to police. These conversations can all be used as evidence against you. You may need to give the bond company basic information about the charges against you, but resist the urge to explain yourself. Talk to a lawyer before you talk to anyone else.

Frequently Asked Questions

What's The Definition of "Intoxicated"?

The Texas Supreme Court has defied intoxicated in three ways: 1). Not having the normal use of one’s mental faculties; 2). Not having the normal use of one’s physical faculties; or 3). Having a breath or blood alcohol concentration of 0.08 or more. A person may be intoxicated on alcohol, drugs, dangerous drugs, prescription medication, over the counter medication, controlled substances or any combination thereof. It’s not a defense that you are on drugs and not alcohol. You can even get a DWI for taking your prescribed medication or over-the-counter medications!

What's The Definition of "Normal"?

Actually, case law specifically prohibits the court from defining normal. That being said, the district attorney is allowed to argue that normal refers to an average person’s abilities. However, the skilled trial lawyer will be able to show that just because you are not necessarily average, whatever that is, that you are still normal and were acting within your normal mental and physical faculties. Things to keep in mind: level of education, learning disabilities, mental illnesses, physical injuries or handicaps, and just general clumsiness, nervousness or inexperience with the tests. Additionally, fevers, dental work, GERD or acid reflux disease, liver or kidney damage, and blood issues may all affect a blood or breath alcohol concentration level.

Our Notable Victories

0.161 BLOOD TEST!!! Client came down from Dallas for the weekend. Checked into his AirBnB and then headed for the Strand. Didn’t know that it was Biker Weekend in Galveston and the Strand was packed. The client left about 11pm and was pulled over by UTMB police for failing to signal a lane change on Broadway. However, the video also showed the police officer doing the exact same thing. Client admitted to drinking and was wearing a “Fuck It, Let’s Drink” shirt. Officer called in a DWI officer and had client step out for the SFSTs. The officer performed the HGN while the client was facing many cars passing in close proximity. But of course, she said he exhibited 6 out of 6 clues (they always say that). The client then performed the Walk and Turn and looked great. Only barely failing the test according to the officer’s own clues. The client then passed the One Leg Stand. Client requested a lawyer when asked for blood and they got a warrant. Blood came out of Harris County DPS with Rachel Aubel testifying. Of course Ms. Aubel testified that she didn’t make any mistakes and her work was performed accurately. She even gave herself 100% in never mixing up a sample in 5 years and 10s of thousands of vials.

Amanda Culbertson, our toxicologist, was able to show how they routinely violated their SOPs and their standards were out of tolerance. The overzealous DAs tried very hard to keep Ms. Culbertson off the stand or prohibit her testimony, but the Judge saw through their antics and let the jury hear the whole truth. Of course, Ms. Aubel rebutted that everything was still perfect even after we exposed all the problems with their lab. This I why we need independent labs! NASA makes mistakes, but police/government labs won’t ever admit anything is wrong. The jury ultimately threw out the blood test and simply said the client didn’t’ look anywhere close to twice the legal limit. Something had to be wrong, it just didn’t add up. They also noted how he could look great on all the tests we could see with our own eyes, but fail the HGN with every clue. Didn’t add up. Thank you to the jury for standing up for the People of Galveston County and demanding better forensic science. Thank you for giving my client his freedom back after 18 long months.

Not Guilty

STATE V. C.R.

Harris COUNTY #5

Attorney: Mark Thiessen

DWI 1st. .116 BREATH TEST! NOT GUILTY!!! Thank you to the jury for standing up for this man, because he never stood a chance with the Officers. Client was called in by a concerned citizen. A police officer happened to pull up next to the caller and the caller said “this guys drunk!” Not knowing that my client was a 63 year old Spanish speaker who had problems with his night vision. Client was pulled over by a vehicular assault task force member on Cinco De Mayo and was Hispanic...

NO TEST, NO ACCIDENT! My client went to the Yankees/Astros game 6 on October 20th, 2017. He arrived at around 6pm and had dinner at Home Plate. During the game, he admitted to having 3 to 4 beers in total. After the game, my client waited the crowd to die down and the celebration to end before making his way to his parked truck. After fighting traffic, he was traveling home and passed a few cars, by speeding up. A Deer Park police officer saw him and followed him for a bit. On video, my client did not commit one traffic offense when the officer pulled him over. My client immediately pulled his car over and was very polite to the officer. After my client admitted to drinking at the ball game, the officer initiated a DWI investigation and was subsequently arrested.

During trial, the officer said my client had slurred speech, red bloodshot eyes, and a strong odor of alcohol on his breath. During the HGN portion of the SFST, the officer had my client looking at a train as he was administering the HGN (6/6). My client did horrible on the WAT 7/8 and OLS 3/4. My client refused to give a sample of breath and the officer decided not to get a warrant for blood. On cross-examination, the officer admitted my client did not lose any mental faculties and he did not have slurred speech. The officer also admitted his mistake on the HGN and said he would have done things differently. I argued my client had 3-4 beers over a 5-hour span and did not lose his mental faculties. The jury returned a verdict of “not guilty” in less than 10 minutes.

Not Guilty

TEXAS V. J.A.

Harris County No. 16

Aug 7, 2018

0.226 BLOOD TEST!! Client works at a local bar and was on his way home at 4am Sunday morning. As he was driving home, a dump truck was trying to avoid another car on 45 South. Client had an accident and totaled his truck into a dump truck. An HPD DWI Task Force unit arrived on scene. Client was polite, handed his DL and answered all of her question. Client politely refused to perform Standard Field Sobriety tests stating that his attorney friends told him to never take those. Client was transported off the freeway and the officer again tried to get him to perform the tests. Client was always polite and looked and sounded normal on the video. Under cross examination the Officer finally admitted she arrested him because he smelled like alcohol and refused the tests. (Neither of those are illegal in Texas). A blood warrant was obtained and the analyst was called to testify. Like usual, the Houston Forensic Science Center analyst testified her result was accurate, the procedure was perfect and she made no mistakes. On cross she admitted that in preparing 25k vials she has never made a mistake and gave her performance 100%. The sample right before client’s was almost identical and just a “coincidence” according to the analyst. The analyst admitted she did not DNA test the sample and had no idea if the client even looked 3x the legal limit. She agreed to Dubowski’s chart on what people should look like and admitted she had no reason to think the client had any tolerance. Although we has an expert and the client ready to testify it was not needed. I could see the jurors shaking their head in disapproval of the State’s case for the entire trial. The jury returned a quick two word verdict. Thank you to the jury for following the law and not just blindly trusting in a ridiculous number that made no common sense. It was a strong and just verdict by a great jury to stand up for better forensic science. We truly need an independent lab in Houston who is not afraid to admit mistakes. NASA is not 100%, but the HFSC is? Yeah right!!

Not Guilty

DWI 2ND / TEXAS V. L.J.

Harris County No. 12

Jul 31, 2018

Client was pulled over for allegedly crossing the lines of traffic multiple times and almost hitting a vehicle. The client was also pulled over after the mandatory midnight Harvey curfew by two of the most seasoned HPD Officers on the DWI task force. Client never stood a chance. Thankfully, the DA was able to find the dash cam of the driving in the middle of trial and that video showed that the Client barely touched the diving lines of traffic and never even left his own lane to avoid missing a parked car. This was a classic case of “when you’re a hammer, everything is a nail.” It was a Saturday night, midnight, in Midtown, with the curfew just in effect at midnight, and the client was pulled over by two of the most decorated HPD DWI Task Force Officers. The Officers were very happy to discuss all of their training, awards, arrests and how high up and powerful they were with HPD and the Harris County Das office. But that backfired on them. The jury was able to recognize that these two officers were so high up that the Das couldn’t tell them they were ever wrong. Thankfully we have jury power for this division of Police and Prosecutor and the jury came back in 15 minutes with a Not Guilty. The client was very polite on video and didn’t’ decline any tests, he just wanted to call his step dad (an ex-HPD officer) to ask him what to do. The DA and the Police over exaggerated the clues and signs of intoxication and the jury was able to see right through it. The jury actually came back and said the client should have never even been pulled over. Thank you to that jury for their just verdict. We waited 9 long months and needed their help in this case to clearly divide the power between the Police and the DAs office.

Not Guilty

TEXAS V. T.W.

Denton County #5

Attorney: Mark Thiessen

DWI 2nd .16 BLOOD TEST NOT GUILTY!! Client was pulled over for swerving on her way home. Client was pulled over by the most aggressive DWI police officer in Denton PD. The officer has now since retired and is attempting to help Defense Lawyers in trial. I would never hire her. Because while now she talks about the inaccuracy and unreliability of the HGN test, while she was cross examined she continued to say that it was accurate. The jury caught on fast to her speaking out of both sides...

Intoxicated Manslaughter (Enhanced to 1st Degree with Prior Felony Conviction)

NOT GUILTY on Intox Man, Guilty of Lesser Included DWI

Client was facing 5-99 for an Intoxicated Manslaughter Case enhanced with a prior felony and the jury only found him guilty of the lesser DWI. Went in facing life, walked out with time served. Team Thiessen would like to thank the jury for their verdict and remaining true to their doubts. Client was a .19 four hours after the accident but the accident was unavoidable. Our accident reconstructionist, John Eftekhar, was able to show the decedent pulled out in front of the client .85 seconds before impact. Thank you to Amanda Culbertson, forensic toxicologist, who found 100% undeniable tampering with the blood vials which allowed the jury to not even consider the result. We also would like to thank Jacob Shiffer, John Leo, and Steven Wright who never left our side and gave invaluable insight. And we’d like to thank God for bringing this all together. It was also amazing getting to try this case with my lovely wife and second chair, Taly Thiessen.

Not Guilty

TEXAS V. S.A.

Montgomery County

Attorney: Mark Thiessen

0.112 BLOOD TEST! Client was a young man on his way home, west bound, from a sports bar. Officers had another person pulled over in the east bound lanes. Magnolia PD Officer Landrum wrongfully believed that the client didn’t pull over for their stop. 1. The video showed the client clearly in his west bound lane; 2. You only have to pull over in a lane for an officer on a stop in the same direction of lanes. Officer Landrum had been written up by  plenty of the Montgomery District Attorneys for dishonesty involving their office and DAs. I know this because it was provided to me as Brady notice. Remember, this is a 24 year old man, who has never been arrested a day in his life...

I'm a trial-tested Super Lawyer focused on fighting for my client's freedom. If you hire our firm, we're available 24/7, because, at the end of the day, we work for you.

Mark Thiessen

DWI, Criminal & Civil Trial Defense Attorney

100+

 NOT GUILTY VERDICTS

The information on this website is for general information purposes only. Nothing on this site should be taken as legal advice for any individual case or situation. This information is not intended to create, and receipt or viewing does not constitute, an attorney-client relationship.

© Thiessen Law Firm. All rights reserved.

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733 E. 12 1/2 Street
Houston, TX 77008

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Call 713.864.9000 or fill out the form below for a free consultation.

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733 E. 12 1/2 Street
Houston, TX 77008

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You have 15 days to save your driver's license

Act fast if you've been charged!

If you've been arrested for a DWI, you're facing two cases against you. The first one is the criminal case by the state of Texas, and the other is by the Texas Department of Public Safety to suspend your license.

SCHEDULE A FREE CASE EVALUATION

Notable Victories

NOT GUILTY

STATE V. C.R.

1ST DWI - Harris County #5

Attorney: Mark Thiessen

0.161 BLOOD TEST!!! Client came down from Dallas for the weekend. Checked into his AirBnB and then headed for the Strand. Didn’t know that it was Biker Weekend in Galveston and the Strand was packed. The client left about 11pm and was pulled over by UTMB police for failing to signal a lane change on Broadway. However, the video also showed the police officer doing the exact same thing. Client admitted to drinking and was wearing a “Fuck It, Let’s Drink” shirt...

CASE DETAILS

NOT GUILTY

TEXAS V. T.W.

DWI 2ND – Denton County #5

Attorney: Mark Thiessen

0.161 BLOOD TEST!!! Client came down from Dallas for the weekend. Checked into his AirBnB and then headed for the Strand. Didn’t know that it was Biker Weekend in Galveston and the Strand was packed. The client left about 11pm and was pulled over by UTMB police for failing to signal a lane change on Broadway. However, the video also showed the police officer doing the exact same thing. Client admitted to drinking and was wearing a “Fuck It, Let’s Drink” shirt...

CASE DETAILS

NOT GUILTY

TEXAS V. S.A.

Montgomery County

Attorney: Mark Thiessen

0.161 BLOOD TEST!!! Client came down from Dallas for the weekend. Checked into his AirBnB and then headed for the Strand. Didn’t know that it was Biker Weekend in Galveston and the Strand was packed. The client left about 11pm and was pulled over by UTMB police for failing to signal a lane change on Broadway. However, the video also showed the police officer doing the exact same thing. Client admitted to drinking and was wearing a “Fuck It, Let’s Drink” shirt...

CASE DETAILS

Mark Thiessen is a bulldog, who would not stop fighting until he got the result I required. His relentless and innovative effort, along with his team, made the difference in getting my case dismissed and expunged. His guidance through a nightmarish experience with a complicated legal system was invaluable.

Nothing less than the BEST!!!

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If you’ve been charged with a crime, you need an experienced and aggressive criminal defense team whose number one priority is positive results for YOU.

Our reputation speaks for itself, and the overwhelmingly positive testimonials on our website will show how we have made miracles happen for accused individuals in desperate need of help. If you want a law firm who will fight for your protection, your freedom and your family, then you must call Thiessen Law Firm.

As one of Houston’s most distinguished criminal defense firms, Thiessen Law Firm emphasizes quality over quantity. We will get to know your case better than anyone and will utilize every tool at our disposal to secure the results you need. We are dedicated to your needs – 24 hours a day, 7 days a week. As soon as you hire us, you will receive the direct contact information on everyone on your case.

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Trial-Tested & Proven Criminal Defense

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