Thiessen Law Firm

Thiessen Law Firm stands as a nationally recognized criminal defense practice known for aggressive advocacy, ethical representation, and exceptional trial results in Houston and throughout Texas. The firm has built a reputation for challenging flawed investigations, exposing unreliable evidence, and protecting individual liberties at every stage of the legal process. Precision, preparation, and strategic execution define each case approach.

Thiessen Law Firm delivers focused representation across DWI defense, criminal law, personal injury, and family law matters. The law firm is particularly distinguished in complex DWI cases, including high-BAC allegations, intoxication manslaughter, and blood and breath testing challenges. Extensive courtroom experience allows the firm to pursue dismissals, not-guilty verdicts, mistrials, and reduced outcomes when trial becomes necessary.

Thiessen Law Firm is led by Mark Thiessen, a trial-tested attorney who is triple board-certified in Criminal Law, DUI Defense, and DUI Law. This rare distinction places the firm among an elite group nationwide. Recognition includes Super Lawyers Top 100 in Texas and Houston, AV Preeminent Martindale-Hubbell rating, Avvo Superb 10.0 score, and National Trial Lawyers Top 100 honors. Scientific training as an ACS-CHAL Lawyer-Scientist strengthens the firm’s command of forensic and evidentiary issues.

Thiessen Law Firm approaches every case with meticulous preparation and disciplined investigation. The firm evaluates officer conduct, forensic procedures, witness credibility, and procedural compliance. Collaboration with co-counsel and expert consultants strengthens trial strategy, while clear communication ensures informed decision-making throughout representation.

Thiessen Law Firm prioritizes confidentiality, honesty, and individualized attention. The firm emphasizes quality over volume, providing direct access to the legal team and availability 24 hours a day. Client priorities guide every strategic decision, whether pursuing trial or negotiating resolution.