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Texas and Colorado. DWI, Intox Assault, Intox Man, ALL Texas Criminal Law. And Colorado DUI and criminal cases around Pitkin County (Aspen)

Mark Thiessen is a distinguished trial attorney who serves as the Chairman and CEO of Thiessen Law Firm, based in Houston, Texas. As of 2024, he is a 15-time Texas Super Lawyer and has been named to the Top 100 Super Lawyers in Houston eleven times and the Top 100 Super Lawyers in Texas six times. His distinction is particularly notable as he was the only DWI lawyer to be selected to the Top 100 Super Lawyers in Texas (2019-2025) and Houston (2017-2025). Thiessen has achieved the remarkable distinction of being Triple Board Certified in: Criminal Law by the Texas Board of Legal Specialization (2018), DUI Defense by the National College for DUI Defense as approved through the American Bar Association (2022), and DUI Law by the DUI Defense Lawyers Association (2018). He has also earned the American Chemical Society-Chemistry and the Law (ACS-CHAL) Forensic Lawyer-Scientist designation, which is recognized as the highest form of scientific recognition available for lawyers. Born and raised in Houston, Texas, Thiessen graduated from Texas Christian University in 2000 with a Bachelor's of Business Administration in Marketing. He later studied law at South Texas College of Law (STCL), where he participated in mock trials and campus law societies. His legal education extended internationally as he studied abroad at the International Criminal Law program at the University of Malta, the BPP Law School in London, England, and the University of Hawaii. In 2011, Thiessen founded his own firm, Thiessen Law Firm, where he has built a formidable reputation as an aggressive trial lawyer. His track record is impressive, having won DWI cases ranging from total refusals to intoxication manslaughter cases, including a quadruple intoxication manslaughter case. Thiessen is deeply involved in professional legal organizations, serving as the DWI Committee co-chair and Board member for the Texas Criminal Defense Lawyers Association (TCDLA). He was the 50th President of the Harris County Criminal Lawyers Association (HCCLA) and serves as a Charter Member, Treasurer, and Director for the DUI Defense Lawyers Association (DUIDLA). Beyond his courtroom achievements, Thiessen is a frequent legal seminar lecturer, author of numerous published legal articles, and faculty member for various organizations. His expertise is particularly focused on intoxicated-related accidents due to his scientific knowledge and background. Outside of his legal practice, Thiessen is a black belt in Brazilian jiu-jitsu, training at Brazil-021 School of Jiu Jitsu in Houston, and also practices Muay Thai. He is an avid snow skier, tennis player, and waterman who splits his time between Texas and Colorado, where his family has maintained connections since 1985. Above all, Mark values spending time with his wife, Taly, and their two children. Fellow attorneys describe him as "one of the top DWI lawyers in the country" and admire his mastery of OWI/DUI defense, energetic presentation style, and personable nature. Colleagues note that "a lot of lawyers know the science but do not know how to try cases with it. Mark knows both — better than anyone."

1996 Kinkaid Highschool 2000 TCU - BBA in Marketing 2003 South Texas College of Law - JD

over 140 DWI NG verdicts ranging from total refusal to Quadruple Intoxicated Manslaughter

Many high profile Intox Manslaughter Cases. And the Liver King against Joe Rogan for Terroristic Threat.

Check out my website for all of my Speaking Engagements. Board Certified in DUI Law by DUIDLA/ Board Certified in Criminal Law by TBLS/ ACS CHAL Lawyer Scientist