Prior to starting Anderson & Thomas, PLLC, with fellow former State District Judge Devon Anderson, Brock served as presiding judge of the 338th Criminal District Court of Harris County, Texas, from August of 2002 to December of 2008. During his time on the bench, Brock presided over literally thousands of felony criminal cases, including drug cases, intoxication assault cases, intoxication manslaughter cases, white collar crimes, thefts, robberies, aggravated assaults, murders, capital murders, and just about every other type of felony case imaginable. In addition to those duties, Brock also volunteered his time to preside over the STAR II (Success Through Addiction Recovery) Felony Drug Court - one of Harris County's innovative and highly effective drug rehabilitation courts.

Before his appointment to the bench in 2002, Brock served as an Assistant District Attorney with the Harris County District Attorney's Office from 1993 until 2002. During his time with the District Attorney's Office, he prosecuted all levels of criminal cases - everything from misdemeanor cases to capital murder cases. Brock also served a stint as a prosecutor within the Public Integrity Unit of the District Attorney's Office where he prosecuted cases involving public officials in their official capacity. At the time of his appointment as Judge of the 338th, Brock served as a felony chief prosecutor.

Brock is an active member of the Houston Bar Association where he has served on several committees. He is also a fellow of the Texas Bar Foundation. Besides being licensed by the State Bar of Texas, Brock is also licensed to practice in federal court in the Southern District of Texas. Brock has also been a speaker and panel member at various continuing legal education seminars on criminal law. Some of those include: "What You Need to Know About Trying Drug Cases" (panel member) Defending Drug Cases Seminar. National Association of Criminal Defense Lawyers. November 13, 2008; "Sentencing Alternatives: Deferral, Probation, Shock Probation, Creative Conditions, Etc." Advanced Criminal Law Short Course. University of Houston Law Foundation. September 20, 2007; and "State Felony Courts: How They Function." Learn From The Masters Criminal Law Conference: What Every Civil Lawyer Should Know About Criminal Law. South Texas College of Law. June 26, 2006.

Brock received his undergraduate degree from the University of Houston in 1990, graduating with honors with a degree in political science. He received his law degree from the University of Houston Law Center in 1993.