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Mark Thiessen

DWI, Criminal & Civil Trial Attorney

Biography

Mark Thissen

DWI, Criminal, and Civil Trial Attorney

Mark Thiessen prides himself on being an aggressive trial lawyer. If the district attorney will not bargain or justice will not be served by allowing the client to plead guilty, Mark passionately and professionally represents his clients at trial. He has won DWI cases from total refusals up to quadruple intoxication manslaughter. Mark has earned formidable reputation for being a tenacious trial lawyer, and he works hard to maintain that status. 

Since opening Thiessen Law Firm, Mark has continued to add to his growing list of accomplishments. Mark Thiessen was the youngest criminal Super Lawyer in Texas in 2013. As of 2018, 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. He has earned the American Chemical Society-Chemistry and the Law’s (ACS-CHAL) Forensic Lawyer-Scientist designation — the highest form of scientific recognition available for lawyers. 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 is also a frequent legal seminar lecturer, author of numerous published legal articles, and a faculty member for various organizations.


Mark Thiessen was born and raised in Houston, Texas. Mark attended the Village School and St. Francis Episcopal Middle School before graduating from the Kinkaid School in 1996. Mr. Thiessen then attended and graduated from Texas Christian University in 2000 with a Bachelor’s of Business Administration in Marketing. While at TCU, Mark was a member of Phi Delta Theta fraternity and on the dean’s list.

Following his time at TCU, Mr. Thiessen returned to Houston and began his law school education at South Texas College of Law (STCL). Mark made the most of his time at STCL, actively taking part in mock trials and campus law societies. Mark’s passion for the law also took him abroad: he has studied at the International Criminal Law at the University of Malta, the BPP Law School in London, England, and at the University of Hawaii. Studying in these unique legal environments required Mark to adapt to various social, cultural, ethnic, and economic groups, which is evident in his approach and personality to this day.

After graduating from law school, Mark practiced civil law at Bell, Ryniker & Letourneau and at Brown Sims, P.C. In 2006, he followed his passion for criminal law by joining the team at Trichter & Murphy, P.C., where Mark was able to study under some of the foremost legal authorities in Texas. After five years with Trichter & Murphy, P.C., Mark decided to start his own law firm, thus opening Thiessen Law Firm. 

Although his practice includes all areas of criminal defense, Mr. Thiessen maintains an emphasis on cases regarding DWI, drugs, and controlled substances. The trial of a DWI case dictates that, on any given date, a trial lawyer must be not only well-versed in Rules of Evidence, case law pertaining to DWIs, and constitutional law, but also numerous areas of science such as anatomy, physiology, toxicology, chemistry, computer science, biology, and physics. 

Mark is the current DWI Committee co-chair and on the Board of Directors for the 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’s reputation for fearlessness extends beyond his presence in the courtroom. In his free time, he competes in Brazilian jiu-jitsu, muay Thai, and participates in competitions such as the Warrior Dash and Tough Mudder. 

If you have a case and want an attorney who does not back down, call Mr. Thiessen today: 713-864-9000.

Honors

Texas Board of Legal Specialization in Criminal Law
Super Lawyers
Lawyer Scientist
Avvo Rating
AV Preeminent
TCDLA
Dui Defense Lawer
National College
National Trail Lawyer
Super Lawyers
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Publications

Mar 9, 2018

TCDLA Voice for the Defense; pg. 23

Article: Not Guilty v. Cerberus: Winning Intoxicated Manslaughter Trials

Jan 26, 2018

5th Annual Lonestar DWI Seminar

Presentation: Not Guilty v. Cerberus; Winning Intoxicated Manslaughter Trials

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Media

May 6th, 2019

Taly Thiessen on Isiah Factor – Uncensored: Are Child Support Payments Fair?

April 5, 2019

‘An emotional release’: Team of lawyers cheer decision to drop all charges in infamous Waco biker shootout

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Press Releases

Sep 28, 2017

Houston Attorney Mark Thiessen Wins Fifth Consecutive Super Lawyers Award and Makes Top 100 Lawyers in Houston

Criminal Defense Attorney Mark Thiessen is the only DWI Attorney to rank in Top 100 for prestigious Thomson Reuters Award

Oct 24, 2016

Attorney Mark Thiessen Receives 4th Consecutive Super Lawyers Honor

Houston lawyer recognized by peers for professional excellence

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Speaking Engagements

San Diego, CA

DUIDLA Fall Seminar

Defending BWI Cases

Orlando, FL

Florida Bar Association Criminal Law Seminar

Intoxicated Manslaughter

Houston, TX

CCCL Judicial Education Conference

Current Updates on DWI Issues

Dallas, TX

State Bar of Texas Advanced Criminal Law Course

Intoxicated Manslaughter Cases

San Antonio, TX

TCDLA 32nd Annual Rusty Duncan Advanced Criminal Law Seminar

Intoxilyzer 9000 and NEW Defenses

Dallas, TX

TCDLA 12th Annual DWI Defense Seminar

Houston, TX

STCL Professor Moses’ Class on Openings and Closings

Huntsville, TX

TCDLA Trial College

Closing Arguments

Austin, TX

TCDLA 6th Annual Lonestar DWI Forensics

BWI Defenses

Austin, TX

State Bar of Texas

Handling Your First (or Next) DWI Case: Handling Breath/Blood Test Analysts

Round Top, TX

TCDLA Round Top VIII Advanced Skills Training

Psychodrama in DWI Cases

Austin, TX

TCDLA 16th Annual Forensics Seminar

Accident Reconstruction

Houston, TX

Harris County Public Defenders Office CLE

Defending Intoxication Related Crimes

Philadelphia, PA

DUIDLA Fall Seminar 2018

Not Guilty v. Cerberus; Beating Intoxicated Manslaughter Cases

Houston, TX

TCDLA Top Gun DWI Seminar

Top 10 DWI Trial Tactics to Shooting Down the State’s Case

San Antonio, Texas

TCDLA Rusty Duncan Seminar

Not Guilty v Cerberus: Beating Intox Manslaughter Cases

Huntsville, TX

TCDLA 42nd Annual Tim Evans Trial College

Instructor

Austin, TX

TCDLA Lone Star DWI

TIED FOR #1 SPEAKER: Beating Intoxicated Manslaughter Cases: Not Guilty v Cerberus

Lubbock, TX

TCDLA Prairie Dog Seminar

Attacking Blood Labs and Beating Intoxicated Manslaughter Cases

Charleston, NC

DUIDLA: Fall Seminar

Voir Dire & Cross in Blood Test Cases

Houston, TX

TDLA Top Gun DWI Seminar

Speaking with DA on DWI Trial Tactics. Voted #1 Speaker for this speaking engagement

Houston, TX

HYLA

How to Successfully Start and Manage a Law Firm

Houston, TX

State Bar of Texas

Advanced Criminal Law Seminar: Intoxilyzer 9000

San Antonio, TX

TCDLA 30th Annual Rusty Duncan Advanced Criminal Law

Intoxilyzer 9000

Houston, TX

South Texas College of Law

Professor Moses’ Openings and Closings Class: DWI Trial Tactics

Houston, TX

TCDLA Training Day

CLE: DWI Pretrial Motions to Suppress

Columbus, OH

Ohio Association of Criminal Defense Lawyers Best in the Midwest

Ohio Advanced DUI Seminar- Defense v. Prosecution DWI Techniques

Caribbean Sea

TCDLA President’s Cruise

CLE: Attacking the Drug Recognition Expert

Lubbock, TX

TCDLA Prairie Dog Seminar

Attacking the DRE Expert

San Antonio, TX

Stuart Kinard Memorial Advanced DWI Seminar

TIED FOR #1 SPEAKER: Defense v. DA Trial Tactics with Bexar County DA Nico LaHood

San Antonio, TX

TCDLA Stuart Kinard Advanced DWI Seminar

Speaking with Bexar County District Attorney Nico Lahood on DWI trial strategies from both sides

Tunica, MS

Tennessee Association of Criminal Defense Lawyers Annual DUI Seminar and Training

Not Guilty v. Goliath; Taking Down High Blood Tests Using the Disconnect Defense.

Houston, TX

TCDLA Top Gun DWI

Intoxilyzer 9000

San Antonio, TX

SACDLA Seminar

Intoxication Manslaughter Trial Tactics

Austin, TX

TCDLA 3rd Annual Lonestar DWI

TIED FOR #1 SPEAKER: Candida Albicans and the Autobrewery Syndrome

Dallas, TX

State Bar of Texas 42nd Annual Advanced Criminal Law Seminar

DWI Trial Tactics and Case Law Update

San Antonio, TX

TCDLA 29th Annual Rusty Duncan Seminar

TIED FOR #1 SPEAKER: DWI Voir Dire From Full Refusals to Intoxicated Manslaughter

Salt Lake City, UT

Utah Association of Criminal Defense Lawyers Advanced DWI Seminar

Not Guilty v. Goliath, Taking Down High Blood Tests Without an Expert

San Antonio, TX

TCDLA DWI Defense Project

DWI Blood Cross-Examination

San Antonio, TX

TCDLA, SACDLA, SABA 53rd Annual Anees Semaan Advanced Criminal Law Seminar

DWI Voir Dire From Full Refusals to Intoxicated Manslaughter

Columbus, OH

Ohio Association of Criminal Defense Lawyers Best in the Midwest

Not Guilty Versus Goliath; Taking Down High Blood Tests Using the Disconnect Defense

College Station, TX

TCDLA Upholding Justice One Client at a Time

VOTED #1 SPEAKER: DWI Techniques

San Antonio, TX

TCDLA Stuart Kinard Memorial Advanced DWI Seminar

Attacking the DRE Expert

Little Rock, AR

Pulaski County Bar Association – DWI Institute: My Case is a Wreck

Not Guilty v. Goliath & DWI Blood Test Disconnect Defense

Austin, TX

TCDLA 2nd Annual Lone Star DWI: Drugs

DWI Hallucinogens and Stimulants & Intoxilyzer 9000

Chicago, IL

DUIDLA

Blood Test Disconnect Defence and Cross Examination Techniques

San Antonio, TX

28th Annual TCDLA Rusty Duncan Seminar

Blood Testing Science and Case Law

Arlington, TX

TCDLA DWI Defense Project

TIED FOR #1 SPEAKER: Cross Examination of the Blood Analyst

San Antonio, TX

TCDLA, SACDLA, SABA 52nd Annual Anees Semaan Advanced Criminal Law Seminar

Not Guilty v. Goliath; Taking Down High Blood Tests Using the Disconnect Defense

Waco, TX

TCDLA Training Your Defense Team to Win

Jury Selection

Lubbock, TX

Annual Prairie Dog Advanced Criminal Law

TIED FOR #1 SPEAKER: Not Guilty v. Goliath; Taking Down High Blood Tests Using the Disconnect Defense

Denton, TX

Jolly Roger Seminar

DWI Blood Trial Tactics

San Antonio, TX

2014 Stuart Kinard Memorial Advanced DWI Seminar

VOTED #1 SPEAKER: Not Guilty vs. Goliath, Taking Down High Blood Tests with the Disconnect Defense

Dallas, TX

TCDLA: Cross Examination

TIED FOR #1 SPEAKER: Cross of DWI Blood Expert

Houston, TX

TCDLA: Top Gun DWI Seminar

Blood Test Voir Dire & Preparing the Jury for Acquittal

South Padre Island, TX

TCDLA Member’s Trip

VOTED #1 SPEAKER: Not Guilty vs Goliath & Taking Down High Blood Tests Using the Disconnect Defense

Austin, TX

TCDLA Lone Star DWI

VOTED #1 SPEAKER: Blood 101: Basics of Blood Testing & Taking Down High Blood Tests Using the Disconnect Defense

San Antonio, TX

27th Annual TCDLA Rusty Duncan Advanced Criminal Law Course

DWI Blood Testing Basic; What Works and What Doesn\'t

Humble, TX

Houston Bar Association at Summer Creek High School

Sex, Drugs and Alcohol; Keeping Kids Scared Straight

Longview, TX

TCDLA Trial Strategies that Work

VOTED #1 SPEAKER: Opening and Closing Statement

Houston, TX

Harris County Municipal Justice Bar Association Annual CLE

Trial Tactics From the Trenches

Houston, TX

Third Annual Hon. Craig Washington & Sen. Rodney Ellis Criminal Law Seminar

Advanced Trial Techniques

Lubbock, TX

TCDLA 33rd Annual Prairie Dog Lawyers Advanced Criminal Law

Basics of Blood Testing to Taking Down Big Blood Tests; How We Do It

Humble, TX

Houston Bar Association at Summer Creek High School

Knowing Your Rights; Sex, Drugs, DWI and Assault

Houston, TX

Houston Bar Association at Westside High School

Mock Trial Voir Dire

Houston, TX

TCDLA / Public Defender’s Office

Indigent Defense Advanced Trial Tactics

Houston, TX

TCDLA Top Gun DWI

10 Silver Bullets for DWI Trials

South Padre Island, TX

TCDLA Gideon’s Trumpet Seminar Series

Basics of Blood Testing; Attacking a DWI Blood Test

Houston, TX

HCCLA Training Day: Criminal Law 101

Trial Tactics from the Trenches

Arlington, TX

TCDLA DWI Defense Project

Basics of Blood Testing; Attacking a DWI Blood Test

Houston, TX

Harris County Public Defender

Closing Arguments – Storytelling

Waco, TX

TCDLA Gideon’s Trumpet Seminar Series

Basics of Blood Testing; Attacking a DWI Blood Test

Humble, TX

Houston Bar Association at Summer Creek High School

Knowing Your Rights; Sex, Drugs, DWI and Assault

Houston, TX

Harris County Public Defender

Closing Arguments – Storytelling

Houston, TX

Westlaw Ed. Center National Webinar

Basics of Blood Testing; Attacking a DWI Blood Test

Houston, TX

Houston Bar Association

Trial Tactics from the Criminal Trenches

Lubbock, TX

TCDLA 32nd Annual Prairie Dog Lawyers Advanced Criminal Law

Basics of Blood Testing; Attacking a DWI Blood Test

Humble, TX

Houston Bar Association at Summer Creek High School

The Importance of Jury Service and Knowing the Law

Georgetown, TX

TCDLA Gideon’s Trumpet Seminar Series

Basics of Blood Testing; Attacking a DWI Blood Test

Houston, TX

TSU Thurgood Marshall School of Law

Criminal Trial Clinic – DWI Trial Tactics and Voir Dire

Austin, TX

TCDLA TOP GUN DWI Seminar

Cross-Examination of Breath Test Technical Supervisor

Houston, TX

Harris County Criminal Lawyers Association CLE

Trial Tactics from the Trenches

Dallas, TX

TCDLA Boot Camp for Young Lawyers

DWI Trial Tactics and Skills

Houston, TX

TSU Thurgood Marshall School of Law

DWI Nuts and Bolts – DWI Voir Dire on High Breath Test with Accident

Houston, TX

TCDLA Voir Dire Seminar

Car Accidents and Hospital Enzymatic Assay Blood Testing

Houston, TX

Texas Criminal Defense Lawyers Assoc.’s Top Gun DWI Seminar

Final Argument

South Padre Island, TX

TCDLA Art of War Trial Tactics

The Game of Trial; Running the Bases

Houston, TX

South Texas College of Law Advanced Advocacy Class

The Game of Trial; Running the Bases

Tyler, TX

TCDLA Art of War Trial Tactics

The Game of Trial; Running the Bases

Edinburg, TX

TCDLA Art of War Trial Tactics

The Game of Trial; Running the Bases

San Antonio, TX

National College of DUI Defense/Texas Criminal Defense Lawyers Assoc.’s Stuart Kinard Advanced DWI Seminar

TIMBER! Chopping Down High Breath Tests without an Expert

Houston, TX

Network of Professional Brazilians in Houston

Understanding Your Rights in Texas and Secrets to Avoiding a DWI Arrest and Conviction

Houston, TX

North Shore Senior High School

Keeping Students Safe from DWI and Drugs

Galveston, TX

Galveston County Criminal Defense Lawyers Assoc. CLE

TIMBER! Chopping Down High Breath Tests

Conroe, TX

Montgomery County Criminal Defense Lawyers Assoc. CLE

New Issues in Montgomery County – Death to the \"E\" Jury; Getting a Fair Trial

Dallas, TX

David Burrows DWI Defense Project

The Game of Trial; Running the Bases

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