Mark represents plaintiffs and defendants in business litigation disputes heard in state and federal courts and arbitration proceedings. His experience includes cases involving breach of fiduciary duty, fraudulent or negligent misrepresentation, misappropriation of trade secrets, securities violations, civil theft, shareholder derivative rights, partnership breakups, and oil and gas disputes. Mark also prosecutes and defends claims for personal injury or wrongful death, as well as represents individuals and entities in state and federal white-collar criminal investigations conducted by the Texas Department of Insurance, Internal Revenue Service, Securities and Exchange Commission, and U.S. Department of Justice.

Mark previously served in the United Sates Marine Corps, where he was assigned to Diplomatic Security with the U.S. embassies and consulates around the world.