Who Is Dennis

Dennis Casillas was born in San Antonio, Texas in November of 1963 to Baltazar and Guadalupe Casillas. He is a lifelong resident of Bexar County. His father and family were sharecroppers who grew up on the near eastside of San Antonio off Sherman and Hackberry Street. Dennis’ parents were both persevering people in their careers. His father, a veteran during the Korean War served in the US Army for 40 years. Dennis’ mother prior to her retirement worked in the retail sale’s industries for 35 years.

Dennis married Zulma Casillas, a Colombian national in December of 2019.Together they share a blended family, 25-year-old son Dante Casillas, 22-Year-old daughter Gabriella Uribe, Son in law Sergio Herrera and grandson Joaquin Herrera and a 15-year-old daughter Isabella Corrales.

From Left to Right: Daughter Isabella, Wife Zulma, Dennis, Son Dante

Dennis grew up near the westside of San Antonio on Las Palmas Dr. At age six, his family relocated near Military Dr. and Marbach Rd.

In December of 1980, while a high school junior, Dennis enlisted in the Texas Army National Guard. Dennis graduated from John Jay High School in 1981, he left for the US Army Basic Training at Ft Jackson, S.C. and later trained as a UH-1 Helicopter Mechanic/Crew Chief at Ft Rucker, Alabama. 

Dennis is the third of four siblings all graduates of John Jay High School. An older brother, Daniel Casillas served in the US Navy during the Vietnam war. In 2013, Daniel passed away from cancer. Two sisters, Diana Casillas Morey employed 44 years with American Airlines and Debra Casillas Henderson who served 22 years in the US Air Force and is currently with the Air National Guard at Joint Base Lackland. A family of dedication and service.

Upon his return from the service, Dennis became a Volunteer firefighter in Bexar County. Two year later at the age of nineteen, he began his career at the Bexar County Sheriff’s Office. Dennis continued his Service in the Army National Guard and completed two six-year enlistments. Dennis served under seven Sheriffs in his 37-year career span, having served six years as a detention officer, four as a patrol officer, four as a Detective, eight as a Patrol Sergeant (earning his Master Peace Officer Certificate December 2003). Dennis served twelve years as a Patrol lieutenant, and then promoted to a Command Staff position in January of 2017, he served over three years as Deputy Chief over the Strategic Operations Division and his last year and three months as Deputy Chief over the Patrol West Substation.

Dennis currently has over 3900 hours of Law enforcement training. He has a Master Peace Officer and Master Jailer Certificate and holds the Meritorious Service Award from the County of Bexar. In July of 1989, Dennis, and Staff Attorney (for Harlon Copeland), Mark Dalipaiz created the Bexar County Sheriff’s Office SWAT team.

Dennis’ had a 20 plus year tenure with the SWAT team. He started with four years as an operator, eight years as the SWAT Sergeant, six years as the SWAT Lieutenant and two years as the Chief in command of the SWAT unit in his Strategic Operations Division.

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Chief Dennis Casillas

For Bexar County Sheriff 2024

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