Mr. Mark Miller began serving as Director of the Schreiner Institute at Schreiner University in August of 2025.  Before joining Schreiner University he served as the Head Coach of Hill Country Endurance, an endurance training company specializing in training multisport endurance athletes.

Mr. Miller originally hails from Timpson, Texas, and attended the United States Military Academy at West Point, graduating in 1996 with a Bachelor of Science Degree in Systems Engineering.  Mr. Miller was commissioned an Infantry officer in the United States Army following graduation from West Point.

During his time in the U.S. Army, Mark commanded both Infantry and Cavalry units, with five overseas combat deployments both in command and staff positions.  Mr. Miller attended the School of Advanced Military Studies (SAMS) Program in 2008 and graduated with a Master of Arts in Military Operations.

Following retirement from the U.S. Army, Mark served as the Track and Field and Cross-Country Coach at Central Texas Christian School for 3 seasons before moving to Germany for five years, working as both a Student Ministry Director and USA Triathlon coach serving the military community in Germany before relocating to the Fort Benning, Georgia area with his spouse Beatrice, who is also a military veteran and Physician Assistant serving the military community.

Mark currently lives in Kerrville and enjoys spending time outside, running and triathlon, and continuing to serve through working with both the Corps of Cadets, veterans, and their dependents at Schreiner University.

Mrs. Chastity V. Howard assumed the role of ROTC Coordinator at Schreiner Institute, Schreiner University, in August 2025. Prior to joining the university, Mrs.
Howard served actively as a Biomedical Science Corps (BSC) officer with the Defense Health Agency. She holds a Master of Science degree in Clinical Laboratory Management from the University of Southern Mississippi.

Commissioned into the U.S. Air Force in 2005, Mrs. Howard’s distinguished 21 year career encompassed various leadership positions, including Element Chief,
Flight Commander, Senior Biomedical Executive, Headquarters Staff, Deputy Squadron Commander, Program Director, and Department Chair. Her assignments spanned multiple locations and included both deployed and peacetime roles, all contributing to the advancement of medical optimization in military operations.

A member of the most diverse corps in the Air Force, Mrs. Howard engaged in research, held key leadership responsibilities within the Air Force Medical Service and the Defense Health Agency, and supported the transition of Military Treatment Facilities to DHA management, thereby promoting integrated support for combatant commanders. As an invited lecturer for the Society of American Federal Medical Laboratory Scientists Symposium, she shared her direct experiences and contributions during Hurricane Katrina. Her exemplary service was recognized by being named BSC of the Year, receiving the Humanitarian Service Medal, and earning commendation from the USAF Surgeon General.

Following her retirement from active duty on July 31, 2025, Mrs. Howard resides in Kerrville with her husband and two sons. She enjoys cooking, crocheting, and spending quality time with her family.

Mrs. Howard remains committed to service by supporting students and veterans, equipping them with the skills necessary to succeed—whether through participation in the Reserve Officer Training Corps or by joining a community that fosters professional and personal growth.

Timothy McGuire is a retired U.S. Navy Chief with 22 years of distinguished service as a Flight Safety Officer and Protestant Lay Leader. A decorated veteran and Master Training Specialist, he received multiple commendations for excellence in leadership and training.

After transitioning from military service, Tim dedicated his life to ministry, education, and leadership development. He holds a degree in Biblical Studies from Liberty University and is pursuing graduate studies in Educational Leadership and Christian Ministry. He has served as a worship minister in several states and continues to serve faithfully at the San Jose Church of Christ.

Currently, Tim serves at Schreiner University in Kerrville, Texas, as Coordinator for the Schreiner Institute, Head Coach of the NCAA Division III Rifle Team, and Coordinator of the Mountaineer Leadership Academy. His leadership emphasizes mentorship, academic growth, and character development for students preparing for civilian and military service.

An author and content creator, Tim leads the New Beginnings ministry, podcast, and YouTube channel, inspiring others through biblical teaching and personal testimony. His published works include On the Battlefield and A Worshiper’s Journey, with additional titles in development exploring faith, resilience, and restoration.