Mark Diaz

Texas

Mark Diaz & Associates
719 59th Street
Galveston, TX 77551
United States

Tel: (409) 204-0104

Email: mark@texascriminaljustice.com
Web: www.texascriminaljustice.com

Professional Biography

Mark Diaz is a criminal defense attorney who has spent nearly three decades standing between his clients and the State of Texas. Throughout his career, he has represented individuals facing the full spectrum of criminal charges, bringing seasoned judgment and steady leadership to cases where the stakes are often life-changing.

For many people, an arrest or prosecution is overwhelming and unfamiliar. Mr. Diaz understands that most of his clients have never set foot in a courtroom before. His extensive experience across a wide range of criminal matters allows him to remain calm, focused, and strategic when his clients need clarity and confidence the most. Criminal defense is not a secondary practice area for him—it is the sole focus of his professional life and has been since he began practicing law.

Mr. Diaz is a graduate of Thurgood Marshall School of Law and earned his undergraduate degree from the University of Houston. He is admitted to practice in all Texas state courts as well as the United States District Court for the Southern District of Texas. For nearly 30 years, he has aggressively defended the rights of individuals throughout Texas, including Galveston County and the surrounding areas.

In a field where some attorneys compete on price or high case volume, Mr. Diaz has built his practice on a different philosophy: when a client’s freedom, future, and reputation are at risk, the quality of representation matters. Clients who retain him work directly with him. He remains personally involved from arrest through resolution and makes himself accessible, providing clients with direct communication rather than delegating their cases to junior associates or treating them as one file among many.

Known for a direct and no-nonsense approach, Mr. Diaz prepares each case thoroughly, challenges the prosecution aggressively, and pursues favorable resolutions both inside and outside the courtroom. Whether through negotiation, motion practice, or trial, his focus remains on protecting his clients’ rights and seeking the strongest possible outcome under the circumstances.

Mark Diaz & Associates is a seasoned criminal defense firm in Texas, providing exceptional legal representation to individuals facing criminal charges in Galveston County and Harris County. Backed by decades of combined experience and a deep understanding of Texas criminal law, the firm is fully committed to safeguarding the legal rights of its clients and ensuring they receive fair treatment under the law.

Navigating the complexities of the Texas criminal justice system can be overwhelming, particularly when serious charges are involved. Mark Diaz & Associates recognizes that skilled legal representation is critical during such high-stakes moments. The firm offers unwavering support and strategic guidance, understanding that criminal proceedings are often among the most challenging experiences a person can face. Through personalized attention and carefully tailored defense strategies, the team works to reduce the stress and uncertainty that accompany criminal accusations.

Protecting the rights of the accused is at the core of the firm’s practice. Mark Diaz & Associates firmly believes that every individual deserves a fair trial and a meaningful opportunity to defend against allegations. Guided by the principles of justice and fairness, the firm works tirelessly to secure favorable outcomes for its clients. Whether negotiating plea agreements, challenging the admissibility of evidence, or advocating in court, the attorneys remain dedicated to achieving the best possible result in each case.

For individuals facing criminal charges in Galveston County or Harris County, having an experienced defense attorney is essential. Mark Diaz & Associates is committed to delivering the highest level of legal representation, protecting clients’ rights, and pursuing optimal outcomes. The firm is available 24/7 at 409-204-0104 to provide a free consultation and begin building a strong legal defense.

Mark Diaz & Associates provides comprehensive legal representation in a wide range of criminal defense matters. With a wealth of experience and a deep understanding of both Federal and Texas criminal law, the firm is equipped to handle even the most complex cases. Below is a detailed list of the practice areas covered by the firm:

  • Assault and Battery – The firm offers aggressive defense strategies for individuals facing assault and battery charges, working tirelessly to protect their rights and achieve the best possible outcome.
  • White Collar Crimes – The firm has extensive experience defending clients accused of white-collar crimes, including fraud, embezzlement, and insider trading, among others.
  • Sexual Assault – The firm understands the sensitive nature of sexual assault cases and provides compassionate yet assertive representation to defend clients against these serious allegations.
  • Homicide – In cases involving homicide charges, the firm offers strategic defense strategies aimed at securing acquittals or mitigating penalties for clients.
  • Federal Criminal Defense – The firm has a proven track record of success in defending clients facing federal criminal charges, including drug trafficking, racketeering, and white-collar crime offenses.
  • DWI Charges – The firm provides aggressive defense against DWI charges, advocating for clients’ rights and working to minimize the impact of these charges on their lives.
  • Drug Crimes – From drug possession to drug trafficking, the firm offers comprehensive defense representation for clients facing a wide range of drug-related offenses.
  • Drug Manufacturing – The firm has the knowledge and experience to effectively defend clients charged with drug manufacturing, including cultivating, producing, or distributing controlled substances.
  • Drug Trafficking – The firm offers aggressive defense against drug trafficking charges, leveraging their experience and resources to fight for favorable outcomes for clients.
  • Drug Possession – Whether facing misdemeanour or felony drug possession charges, the firm provides skilled legal representation aimed at minimizing the consequences for clients.
  • Burglary, Robbery & Theft – The firm provides strategic defense representation for individuals accused of burglary, robbery, theft, and other property crimes.
  • Domestic Violence – The firm understands the complexities of domestic violence cases and provides compassionate yet assertive representation to protect the rights of clients.
  • Expungement of Criminal Records – The firm is able to assist eligible clients in pursuing expungement or sealing of their criminal records, helping them move forward with a clean slate.

“Mark Diaz is a trusted advocate for individuals facing overwhelming criminal charges. Clients appreciate his calm, no-nonsense counsel during uncertain times, while peers respect his long-standing dedication to criminal defense as his sole professional focus.”
The Criminal Defense Lawyers Guide, 2026