Mark A. Sampson has never prosecuted anyone. Since 1993, his entire practice has been devoted to defending people — in the county courthouses of Central Texas and the federal courtrooms of the Western District of Texas.
The Law Office of Mark A. Sampson P.C. is built on a simple conviction: the cases that are prepared for trial are the cases that resolve well. Every matter that comes through the door is assessed and worked up as if a jury will hear it — meticulously, and early — because knowing the law and knowing the case are the foundation of a proper defense.
Mark graduated from the University of Texas School of Law in 1992 and was admitted to the State Bar of Texas in 1993. In the three decades since, his practice has grown from the misdemeanor and felony dockets of Travis and Williamson Counties into a substantial federal criminal practice in the Western District of Texas — drug and firearm prosecutions, federal sentencing advocacy, and the complicated terrain where state and federal cases intersect.
That distinction matters. Many defense lawyers market their years as prosecutors. Mark's career tells a different story: every argument he has ever made in a criminal courtroom has been made on behalf of the accused. His clients get an advocate whose instincts, relationships, and reputation were all built on the defense side of the docket.
Beyond his own cases, Mark teaches and leads. He served as Presiding Director of the Austin Criminal Defense Lawyers Association for 2024–2025, and he develops and presents training for fellow defense attorneys on federal criminal practice — the Criminal Justice Act panel system, the U.S. Sentencing Guidelines, criminal history analysis, and recent developments in federal sentencing law. When other lawyers want to understand federal practice, Mark is one of the people they learn it from.
Juris Doctor, Austin, Texas.
Opened a defense practice serving Austin and the surrounding counties.
Elected by his peers in the local criminal defense bar.
Continued leadership within the section.
Led the organization at the center of Austin's criminal defense bar — three decades after joining it as a member.
An active trial practice across Central Texas counties and the Western District of Texas, with continuing legal education and training work for the defense bar.
Federal criminal practice is its own discipline — the rules, the timelines, and especially the sentencing system bear little resemblance to state court. Mark develops continuing legal education on navigating federal practice, which keeps his own courtroom work sharp and current.
Valerie Thomas Sampson has served as Business Operations Manager for the Law Office of Mark A. Sampson, P.C. for 26 years, overseeing the firm's day-to-day operations so that clients facing criminal charges get the attention and responsiveness their cases demand.
Before joining the firm, Valerie spent seven and a half years as a Pretrial Services Officer for Travis County and a year and a half as a Juvenile Probation Officer. That firsthand experience inside the county's pretrial and juvenile justice systems gives her a practical understanding of the process clients and their families are going through — from booking and bond conditions to court settings and case coordination.
Valerie holds a Bachelor of Science degree (1989) and a Master of Science in Criminal Justice (1998), both from Texas State University.
Travis County. Worked directly with individuals in the pretrial process, evaluating and supervising defendants released before trial.
Supervised and supported youth in the juvenile justice system.
Member.
Charter Member.
Associate.
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(512) 320-8363