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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
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Rating: 10 Justia Lawyer Rating - 10 out of 10
Mark is the best lawyer I know and a great human being as well. I've learned so much from him, and he's always raising the bar for everybody.
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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
  • DUI & DWI
  • Cannabis & Marijuana Law
  • Personal Injury
  • 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
17 Questions Answered

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.
Q. If two people are order to pay restitution how can you get it divided between the two
A: It's usually left up to your lawyers. Don't take the deal if you aren't willing to pay that back. If the other party is solely to blame, then get your lawyer to communicate that to the DA and see if they will charge the other guy with all of the restitution. But remember, your co-defendant's lawyer is going to be arguing against you that you should split it. Alot of the times the DA just splits the baby and makes yall both pay the same. If you don't like the deal, you can always go to trial. But often, it's just your co-defendant screwing you over again and the DA not wanting to get in the middle of it.
Q. I’m on felony probation an this last year my dad committed sucide an I lost it my mind didn’t show up for po meeting an
A: You can't get the warrant withdrawn all by yourself. Call you attorney and approach in court with him to explain yourself. Expect to be drug and alcohol tested, so be clean. Also bring a death certificate and maybe the funeral information for the Judge. Sorry for your loss.
Q. For a first offense and a clean record of everything... Can a ticket for patronizing a prostitute be kept off my record.
A: Yes you can, but you need to get the case dismissed or found not guilty.
Q. If someone comes to court and claims that the drugs you are being charged with belong to them will the charges against y
A: Not guaranteed. Happens all the time where someone will take the fall. The DA will analyze the case and evidence. If this person is lying, they could be charged with obstruction, perjury, false statement.... lots of stuff so be very careful. Best to hire an attorney and let the attorney present the evidence to the State.
Q. Will the charges be dropped If someone else claims the drugs you are being charged with
A: Depends. Depends on the DA, the evidence and how much they want to believe that other person.
Q. I was wondering what the first step would be to fixing a statement
A: Call his lawyer and talk to his lawyer. As long as you are not represented by a lawyer then his lawyer is free to talk to you. His lawyer can then figure out whether to do an affidavit or get you in touch with the DAs to fix your statement.
Q. Is there a law against the compound tetrahydrocannabinol to make it illegal?
A: So West Virginia law is still governed by Federal US law. THC is still illegal, but some states have legalized CBD and most states can't test the difference between CBD and THC and the concentrations. Unless you are in a state that has legalized marijuana, then ordering THC online is still against the law. May incur federal charges too for crossing state lines. be careful.
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Contact & Map
The Thiessen Law Firm
733 E 12th 1/2 St
Houston, TX 77008
Telephone: (713) 864-9000