Fifteen years after opening with one attorney and a paralegal, Thiessen Law Firm has grown into a multi-office trial practice spanning criminal defense and personal injury across Texas and Colorado.
HOUSTON, Aug. 19, 2026 /PRNewswire-PRWeb/ -- Thiessen Law Firm is celebrating 15 years in business this month, a milestone that traces back to a single attorney, one paralegal, and an office in an attic. Founder Mark Thiessen has since built that operation into a trial practice with multiple offices across Texas and Colorado, and grown the business tenfold since the firm's first year.
Fifteen years of firsts
Thiessen built his name as one of the most decorated DWI defense attorneys in Texas. He holds board certifications in Criminal Law from the Texas Board of Legal Specialization, DUI Defense from the National College for DUI Defense, DUI Law from the DUI Defense Lawyers Association, and Criminal Trial Law from the NBTA Foundation. He is also recognized as an ACS-CHAL Forensic Lawyer-Scientist, and has been named a Texas Super Lawyer every year since 2010.
Over the years, there have been many landmark verdicts, but among them are a Not Guilty verdict in a quadruple intoxication manslaughter case, the dismissal of a terroristic threat charge that alleged influencer Brian "Liver King" Johnson made threats against podcast host Joe Rogan, and a top 10 settlement in all of Texas.
Expanding the fight to personal injury
In 2024, the firm expanded into personal injury law under its We Fight Giants division, taking the same trial-tested approach it built defending criminal clients and turning it on insurance companies and corporate defendants. The results came quickly.
We Fight Giants recovered more than $17.5 million for injured Texans in its second year of operation, and Thiessen was named to two separate lists honoring the largest settlements in Texas for 2025.
Standing up for clients beyond the courtroom
Mark Thiessen's advocacy doesn't stop at the courtroom door. He's maintained a commitment to continued education and advocacy for criminal justice organizations, and consistently shares his knowledge with young attorneys looking to make a difference in their own communities.
Thiessen testified at the Texas Capitol against Senate Bill 2320, a proposal that would have made a first-time DWI with a BAC over 0.15 an automatic felony. Thiessen argued that felony charges should be reserved for cases involving serious harm, repeat offenses, or children in the vehicle, not first-time mistakes by otherwise law-abiding people, a position that put the firm's advocacy ahead of its own short-term business interests. Or as Taly Thiessen, trial attorney at Thiessen Law Firm and Mark Thiessen's wife, said herself, "They trust him because he's arguing against this bill, even though it would be very good for business if it passed."
Looking ahead
Fifteen years in, Thiessen says the firm isn't slowing down. With a growing personal injury practice, an expanding footprint in Colorado, and a criminal defense record built on more than 140 Not Guilty verdicts and thousands of dismissals, Thiessen Law Firm continues to take on cases other firms turn away.
"We've never been the biggest firm in Houston, and we don't want to be," Thiessen said. "We want to be the firm people call when they think there's no way out. Fifteen years in, that hasn't changed, and it's not going to."
ABOUT THIESSEN LAW FIRM
Thiessen Law Firm is a Houston-based trial law firm founded in 2009 by 14-time Texas Super Lawyer Mark Thiessen. Thiessen Law Firm's 140+ Not Guilty verdicts and thousands of cases dismissed established them as one of the nation's elite criminal defense practices before expanding into personal injury law in 2024. The We Fight Giants personal injury division applies the same aggressive trial advocacy to fighting insurance companies and corporate defendants on behalf of injured Texans.
For more information, visit https://www.thetexastrialattorney.com/.
Note to Editors:
For additional information regarding Thiessen Law Firm's results or interview requests with Mark Thiessen, please contact Daniel Ebbs at the provided contact information below.
Disclaimer:
Past results do not guarantee future outcomes. The case results described here are illustrative of matters handled by Thiessen Law Firm and do not constitute a guarantee, warranty, or prediction regarding the outcome of any future legal matter. Every case is different and must be evaluated on its own facts, applicable law, and circumstances.
For more information, please contact:
Daniel Ebbs
(832) 236-2854
Media Contact
Daniel Ebbs, Thiessen Law Firm, 1 (832) 236-2854, [email protected], https://www.thetexastrialattorney.com/
SOURCE Thiessen Law Firm
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