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Mark Ryan Thiessen

Mark Ryan Thiessen

Over 100 Not Guilty Verdicts: Thiessen Law Firm
  • Criminal Law, DUI & DWI, Cannabis & Marijuana Law ...
  • Colorado, Texas
Claimed Lawyer ProfileQ&ASocial MediaResponsive Law

Mark Thiessen is a criminal trial lawyer and the Chairman/CEO of the Thiessen Law Firm in Houston, Texas. Mark is Board Certified in Criminal Law by the Texas Board of Legal Specialization and Board Certified in DUI Law by the DUI Defense Lawyers Association. Mark earned the American Chemical Society-Chemistry and the Law (ACS-CHAL) Forensic Lawyer-Scientist designation, which is the highest form of scientific recognition available for lawyers. Mark is a frequent legal seminar lecturer, author of numerous published legal articles, and a faculty member for various organizations. Mark is the current DWI Committee co-chair and on the Board of Directors for Texas Criminal Defense Lawyers Association (TCDLA), on the Board of Directors for Harris County Criminal Lawyers Association (HCCLA) and a Charter Member and Director for DUI Defense Lawyers Association (DUIDLA). Mark is a 6 time Texas Super Lawyer and in the Top 100 Super Lawyers in Houston (2017 & 18). In 2019, Mark was the only criminal lawyer to be named to the Top 100 Super Lawyers in all of Texas. Mark has won DWI cases from total refusals up to quadruple intoxication manslaughter.

Mark’s reputation for fearlessness extends beyond his presence in the courtroom. In his free time, he competes as a Brown Belt in Brazilian jiu-jitsu, Muay Thai, and participates in competitions such as the Warrior Dash and Tough Mudder. He is also an avid snow skier, wake boarder and tennis player.

Practice Areas
    Criminal Law
    Criminal Appeals, Drug Crimes, Expungement, Fraud, Gun Crimes, Internet Crimes, Sex Crimes, Theft, Violent Crimes
    DUI & DWI
    Cannabis & Marijuana Law
    Marijuana Business Formation, Medical Marijuana
    Personal Injury
    Animal & Dog Bites, Brain Injury, Car Accidents, Construction Accidents, Motorcycle Accidents, Premises Liability, Truck Accidents, Wrongful Death
  • Free Consultation
Jurisdictions Admitted to Practice
Colorado Supreme Court
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State Bar of Texas
ID Number: 24042025
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5th Circuit
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U.S. Supreme Court
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  • English: Spoken, Written
  • Spanish: Spoken, Written
Professional Experience
Thiessen Law Firm
- Current
Trial Attorney
Trichter and Murphy
Brown Sims, P.C.
Bell Ryniker Letourneau & Nork
South Texas College of Law
J.D. | Law
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University of Hawai'i at Manoa William S. Richardson School of Law
Environmental and Admiralty Law
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Texas Christian University
B.B.A. | Marketing
Activities: Phi Delta Theta
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Trinity University
Activities: Omega Phi and Tennis
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Super Lawyer
Super Lawyers
Selected To Super Lawyers: 2013 - 2019
AV Preeminent
Martindale-Hubbel Lawyers Service
Peer Rated for Highest Level of Professional Excellence
Top 100 in Houston
Super Lawyers
Top 100 in Houston
Super Lawyers
Top 100 in Texas
Super Lawyers
Top 100 in Houston
Super Lawyers
Lawyer Scientist
Rising Star
Super Lawyers
Selected To Rising Stars: 2010 - 2013
Professional Associations
Vice President
- Current
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President Elect and Board of Directors
- Current
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DWI Co-Chair and Board of Directors
- Current
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- Current
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State Bar of Texas  # 24042025
- Current
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Articles & Publications
Over 20 Published Works - See My Website, Please
2019’s Need-to-Know Changes to DWI Law
TCDLA Voice for the Defense
Speaking Engagements
Over 70 Speaking Engagements - International
Supreme Trial Tactics, DUIDLA Spring Seminar, Washington D.C.
Board Certified in Criminal Defense
Texas Board of Legal Specialization
Board Certified in DUI Defense
DUI Defense Lawyers Association
Websites & Blogs
Legal Answers
18 Questions Answered

Q. How to find out if my current lawyer is working on my case?
A: Call him/her. Good lawyers will freely talk to their clients and show you what they have done. All lawyers must communicate with their client. If the lawyer won't get back with you then you should hire another lawyer and look at remedies with the State Bar.
Q. I am a woman who was traveling alone to Dallas. I stayed in a hotel alone. I had my handgun in my purse.
A: Yep, that happens. Thankfully TSA was cool and let you return it to your car. I doubt anything happens. Consider it a warning. They usually arrest you and you get a criminal charge at the airport.
Q. My fiancee has been on a probation hold for almost 2 long can they hold her without a charge being filled?
A: So she was on probation, violated allegedly and is still in? That lawyer needs to approach immediately and ask for a bond. They cannot revoke her probation without a hearing. She is usually entitled to a bond, unless very rare circumstances. How did she even get picked up? They have a warrant? and if it was a violation based on prescription meds then that should be easy to beat. Get that lawyer to get her a bond or set it for a hearing date. Sorry to hear you're going through this.
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Contact & Map
The Thiessen Law Firm
733 E 12th 1/2 St
Houston, TX 77008
Telephone: (713) 864-9000