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Mark R. Thiessen

Fighting for the People and Winning.

733 E. 12th 1/2 Street
Houston, TX 77008

Phone: 713-864-9000

Website: thetexastrialattorney.com

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About Mark R. Thiessen

Mark Thiessen is a criminal trial lawyer and the Chairman/CEO of the Thiessen Law Firm in Houston, Texas. Mark is Board Certified in (1) Criminal Law by the Texas Board of Legal Specialization 2018; (2) DUI Law by the DUI Defense Lawyers Association 2018; and (3) DUI Defense Law by the National College for DUI Defense through the American Bar Association 2020. 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), 2020-21 President of Harris County Criminal Lawyers Association (HCCLA) and a Charter Member and Parlimentarian for DUI Defense Lawyers Association (DUIDLA). Mark is a 9 time Texas Super Lawyer and in the Top 100 Super Lawyers in Houston (2017-21). From 2019-21, Mark was the only DWI lawyer to be named to the Top 100 Super Lawyers in all of Texas. Mark has won DWI trials from total refusals up to quadruple intoxication manslaughter.

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Virtual Forensic Library

NCDD members have access to a comprehensive forensic library that provides invaluable information to be used when defending clients charged with DUI.

This library includes scientific articles on drug and alcohol intoxication, toxicology and pharmacology, methods of testing for blood alcohol content, field sobriety testing, potential errors that may occur during testing, accident reconstruction, expert testimony, and evidentiary rules. This valuable information can ensure that you provide a high quality defense to clients charged with DUI based on the circumstances of their case and the laws in their state.

Virtual Forensic Library

FROM OUR BLOG

Introduction of Autonomous Vehicles and SAE Levels of Driving Automation

02/12/2025

By By Lance Hendron An autonomous vehicle, in other words is self-driving car, is a car that is capable of operating with reduced or no human input.1 In 2014, the Society of Automotive Engineers (SAE), launched SAE J3016 Recommended Practice: Taxonomy and Definitions for Terms Related to Driving Automation Systems for On-Road Motor Vehicles, commonly referenced as the SAE Levels of...

Forensic Evidence – it has its limits and sometimes those limits are your weapon

01/30/2025

By By Michael J. Nichols This is a story about Karolyn. Karolyn is a 28-year-old Marine Corps veteran. Karolyn was medically discharged from the "Corps" at 20 years old because a 500-pound bomb fell on her during a training exercise. It did not denotate, but it hurt. It literally concussed her entire body. Fast forward by about 4 years. A number changes...

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Members of the NCDD not only demonstrate that they are qualified DUI defense attorneys, but they have access to valuable information and resources. We provide access to documentation blood alcohol testing devices and scientific articles related to alcohol, drugs, driving, and testing.

We offer training on trial techniques and scientific testing, and we provide access to experts and a comprehensive knowledge base of cases and motions. With all of these resources at your fingertips, you will be able to win more cases

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Depending on your level of experience, we offer multiple plans for NCDD Membership. Attorneys who have been practicing for less than six years are eligible for a New Attorney membership, while those who have been practicing for over six years can receive a Seasoned Attorney membership. We also offer memberships for Public Defenders.