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Mark Ryan Thiessen

About me

Born and raised in Houston, Texas.  Went off to college at TCU and came back home for law school.  I know Houston.  I am raising my family in Houston.  I love Houston.  It's my job to protect the citizens of Houston. 


My favorite part of this job is going to trial.  And, it's that love of trial that gets great results before a trial is necessary.  Too often the State will try and force you into a deal.  Let me analyze the case.  Let me analyze the State.  The State has the burden of proof to prove that you committed that crime beyond a reasonable doubt.  Don't go down without taking a swing of the bat.  But, it's best to bring the biggest bat you can carry. 


I live by my word and will always be straight with you.  When you hire me, I will give you my cell phone number and you can call/text/email me at any time.  Afterall, I work for you.


Languages spoken: Spanish, English

Photos and videos

82475 1291414245

82475 1289345478

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82475 1278531874

Practice areas


  1. DUI & DWI: 70%
    10 years, 500 cases
  2. Criminal Defense: 30%
    10 years, 200 cases



Fixed (always), Free consultation (90 minutes)

Payment types:

Cash, Check, Credit card

Attorney endorsements

64 total 

Are you an attorney? Endorse this lawyer

  • Colin Hobbs

    As a former prosecutor, you always knew that when Mark walked through the door you were in for a fight if you went to trial. He knows his stuff, especially DWI law.


    Colin Hobbs Family Attorney
    Relationship: Opposing Counsel on matter

  • Joshua Hill

    There are many great trial lawyers in Texas and there are many great DWI lawyers in Texas. What really sets Mark apart from the rest of the pack is his ability to be both. Mark has some of the most thorough understanding of all aspects of DWI cases, from the science involved to the applicable laws. Usually, more technical lawyers who understand the science or the law do not also excel in connecting with the common juror or in explaining difficult concepts to a jury or judge. Mark Thiessen is able to bridge this gap very successfully: his trial results clearly speak to this ability. I'm a board certified criminal trial attorney with over a decade of experience and multiple trials under my belt and I still learn and pick up a few tricks when watching Mark in trial or when he speaks at continuing legal education events. I endorse Mark Thiessen - he knows what he's doing.


    Joshua Hill Criminal Defense Attorney
    Relationship: Fellow lawyer in community

Contact info

Thiessen Law Firm

1221 Studewood St.
Houston, TX, 77008


TXEligible To Practice In Texas 200310/19/2015
We have not found any instances of professional misconduct for this lawyer.
Avvo contributions
Legal answers
Award nameGrantorDate granted
Texas Super LawyerThomson Reuters2014
Texas Super LawyerThomson Reuters2013
Texas Rising StarTexas Monthly Magazine2012
Unsung Hero AwardHarris County Criminal Lawyers Association2012
Texas Super Lawyer: Rising StarTexas Monthly Magazine2011
Rising StarTexas Super Lawyers2010
Who's WhoStrathmore2010
Work experience
TitleCompany nameDuration
AttorneyThe Thiessen Law Firm2011 - Present
AttorneyTrichter & Murphy, P.C.2006 - Present
Association namePosition nameDuration
Texas Criminal Defense Lawyers AssociationDWI Committee Chair2013 - 2014
Harris County Criminal Lawyers AssociationBoard of Directors2010 - Present
Team Hoger MMA and Muay ThaiMember2010 - Present
Harris County Criminal Lawyers AssociationMember2008 - Present
Heights Brazilian Jiu Jitsu TeamMember2008 - Present
Texas Criminal Defense Lawyers AssociationMember2007 - Present
National College of DUI DefenseMember2006 - Present
Texas Young Lawyers AssociationMemberN/A
Houston Bar AssociationMemberN/A
Legal cases
Case nameOutcome
State of Texas v. W. S.Not Guilty
State of Texas v. F.K.Not Guilty
State of Texas v. W.HNot Guilty
See all legal cases 
Publication nameTitleDate
The Voice (TCDLA))Not Guilty v Goliath; Beathing High Blood Tests Using the Disconnect Defense2014
HCCLA Defender MagazineFalesly Elevated Ethanol Results Using Hospital Enzymatic Assay Blood Testing2012
The Voice (TCDLA))Falsely Elevated Ethanol Results Using Hospital Enzymatic Assay Hospital Blood Testing2012
HCCLA DefenderBuilding the Disconnect Defense2011
HCCLA Defender MagazineMotion of the Month: Challenging Electronic Juries2010
TCDLA VOICE for the DefenseCatch of the Day: Motion Challenging Jury Array and to Quash Jury Panel2010
Voice for the DefenseCatch of the Day: Defendant's Motion to Protect the Fairness of Future Juries2009
School nameMajorDegreeGraduated
South Texas College Of LawLawJD - Juris Doctor2003
Texas Christian UniversityMarketingBachelor of Business Administration2000
The Kinkaid SchoolN/AHigh School Diploma1996
William S. Richardson School of Law, University of HawaiiN/AN/AN/A
Speaking engagements
Conference nameTitleDate
Prairie Dog SeminarNot Guilty v Goliath; Beating High Blood Tests Using the Disconnect Defense2015
HCCLA CLETrial Tactics From The Trenches2012
Voir Dire SeminarDWI Voir Dire - Accident and Blood Testing2011
TOP GUN DWIFinal Argument - Blood Testing2011
Art of War : Trial TacticsDWI Trial Tactics: Running the Bases2011
Art of War - Survivor Trial TacticsDWI Survival Tactics2011
Stuart Kinard Advanced DWI CLETIMBER! Chopping Down High Breath Tests2010
Network of Professional Brazilians in HoustonUnderstanding Your Rights in Texas and Secrets to Avoiding a DWI Arrest and Conviction2010
Galveston County Criminal Lawyers AssociationTimber!; Chopping Down High Breath Tests2010
DWI, Drugs, Assault, Criminal Mischief and the PromKeeping Students Safe from DWI and Drugs2010
Montgomery County Criminal Defense Lawyers Assoc.Death to the "E" Jury; Getting a Fair Trial2009
DWI Defense ProjectDWI Trial Tactics2009
No refusal debate draws strong opinionsDUIN/A