Thiessen Law Firm

Attorney Mark Thiessen

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 Houston DWI trial lawyer, and he works hard to maintain that status. Mark is licensed and tries cases in Texas and Colorado. 

Since opening Thiessen Law Firm, Mark has continued to add to his growing list of accomplishments. In addition to his widely publicized feats as a winning Houston intoxication manslaughter lawyer, Mark Thiessen was the youngest criminal Super Lawyer in Texas in 2013.  As of 2021, Mark is a 9 time Texas Super Lawyer, 5 time Top 100 Super Lawyers in Houston and 3 time Top 100 Super Lawyers in all of Texas.  For the past two years, Mark has been the only DWI lawyer listed in the Top 100 in Houston and the only criminal Super Lawyer listed in the Top 100 Lawyers in Texas.

Mark is the only lawyer in America who is triple board certified in: 

• Criminal Law by the Texas Board of Legal Specialization
• DUI Defense by the National College for DUI Defense as approved through the American Bar Association
• DUI Law by the DUI Defense Lawyers Association.  

Mark has also 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.

Attorney Taly Thiessen

Taly Thiessen is one of the battle-proven Houston family law and Houston criminal defense attorneys at Thiessen Law Firm. She was born and raised on a ranch in Plains, Kansas. She attended West Texas A&M University, where she played basketball and soccer and graduated cum laude in 2007 with a B.S. in Mass Communications/Broadcasting. Next, she attended law school at Texas Tech University School of Law.

During law school, Taly clerked for the Law Office of Mark Snodgrass, helping with criminal defense, family law, and litigation. She also had an internship with the Innocence Project of Texas, supporting their initiative in overturning wrongful convictions and securing freedom for men and women wrongfully imprisoned for crimes they did not commit.

After graduating from law school, Taly continued her employment with Mark Snodgrass, as an associate in his firm, for the next 5 years. Since that time, she has expanded her practice to include juvenile law and family law cases such as divorce, child custody cases, and child support issues.

While in Lubbock, Taly was the President of the Lubbock Criminal Defense Lawyer’s Association and served on the board of the Lubbock Bar Association. Taly is regularly and actively involved in several civic and charitable organizations, including The Junior League of Lubbock, Paul’s Project, Big Brothers and Big Sisters, and Food2Kids.

Attorney Kacie Penman

Kacie Penman was born and raised in Cypress, Texas, where she was a competitive cheerleader and dancer. For undergrad, she attended Oklahoma State University where she studied strategic communications and international business. She graduated with honors and was a member of the Zeta Tau Alpha sorority.

Kacie then returned to Houston to begin her law school education at South Texas College of Law Houston (STCLH), where she also graduated with honors. During college and law school Kacie took her education abroad by studying in London, England, Prague, Czech Republic and Malta. She enjoys traveling and learning about different cultures and people, which allows her to adapt to a wide variety of situations.

During law school, Kacie clerked for the Law Offices of Hinton and Bailey, helping with white collar criminal defense cases and after graduating from law school she was an Assistant District Attorney for Galveston County. During her time in Galveston, Kacie worked on various criminal cases ranging from misdemeanors to felonies, including DWI’s and assaults up to aggravated sexual assault and murder. She also gained extensive experience in Juvenile law.

Kacie is excited to now begin working with the Thiessen Law Firm to apply her experience in prosecution to defend the rights of those accused. She will walk you through every step of the criminal process and offer zealous and honest representation to all.