Mark Apopot, M.D.

I was born in North Carolina and moved to San Antonio, Texas for primary education. After high school, I moved to the Philippines and received my Bachelors of Science in Nursing and Doctor of Medicine from Saint Louis University in Baguio City. During the Covid-19 Pandemic, I studied rigorously and worked in hypertension and diabetes clinic, a pulmonary and sleep medicine clinic, and a pain and rehabilitation clinic. Over the years of interacting with a wide variety of patient populations, and listening to many life stories, I have grown a heart for primary care and preventive medicine. My burning passion for teaching aligns perfectly with Family Medicine.

A healthy work-life balance is my motto - outside of work I enjoy exercising, videogames, and exploring the food scene


Karim Heras, M.D.

Dr. Karim Heras is a dedicated and compassionate physician who was born in Mexico City and raised in Rehoboth Beach, Delaware. From an early age, he had a passion for helping others, which ultimately led him to pursue a career in medicine.

Dr. Heras attended the School of Medicine at the Universidad Autónoma de Guadalajara, where he discovered the importance of family medicine practice while completing his clinical rotations and community outreach activities. He was deeply moved by the impact he could have on people's lives by providing primary care, preventative services, and health education to underserved communities.

During the COVID-19 pandemic, Dr. Heras worked with NORC at the University of Chicago to aid in the contact tracing initiative for the State of Maryland. He was instrumental in helping to identify and contain the spread of the virus by communicating with individuals who had been exposed and ensuring they received appropriate testing and medical care.

Dr. Heras is now excited to be calling Victoria, TX, his home and is thrilled to be joining the medical resident program. He is committed to providing the highest level of care to his patients and to making a positive impact on the community's health and wellbeing.

With his passion for family medicine, dedication, and strong work ethic, he is sure to make a significant contribution to the field of medicine.


Steven Huffman, M.D.

Dr. Huffman grew up in San Antonio and has lived most of his life in the South Texas community. He received his Bachelors in Biology from University of Texas San Antonio and his Medical Doctorate from Texas Tech School of Medicine. Dr. Huffman then served in the US Navy in Internal Medicine and as the Medical Editor for Navy Medicine West. He believes in a holistic approach to medicine that aims to maximize quality of life and wellbeing. Dr. Huffman is excited to practice in Victoria and hopes to become a valuable part of the community.


Sergio Mejia, M.D.

My name is Sergio Mejia, I was born in the US and raised in Mexico. I attended medical school at Universidad Autonoma de Guadalajara in Jalisco, Mexico. After medical school, I moved back to Houston where I completed one year of pre-internship. During medical school, I was able to understand the importance of preventive medicine. This acknowledgment went even further during my pre-internship because I understood that besides the importance of preventive medicine, there was a deficit in primary care doctors. Being able to complete my residency training at DeTar Family Medicine Program will allow me to achieve all my goals. I will be able to culminate my medical education while helping underserved communities and fighting the primary care doctors' deficit.

Outside of the healthcare setting, I enjoy spending time with my family and friends, road-tripping, and Barbecuing.


Victoria Oneill, D.O.

I was born in Louisiana and moved to Houston, TX during elementary school. I received my bachelor’s degree in Biology from St. Edward’s University in Austin, TX, and my medical degree from The University of the Incarnate Word School of Osteopathic Medicine in San Antonio, TX. Before medical school, I had the opportunity to volunteer, research, and work at a community clinic in Houston. The time I spent with the patients and providers at this clinic helped me realize my passion for Family Medicine and led me to apply to medical school. I am passionate about Family Medicine because it is foundationally about building lifelong relationships with families, working as a team, and serving my community. In my spare time, I love spending time with my family, trying DIY projects, and going to car shows.


Kenneth Roca, M.D.

I was born in Guatemala and grew up in a small town in North Texas. Shortly after graduating high school I decided to pursue my dream of becoming a doctor at Universidad de San Carlos de Guatemala. I met my wife during medical school and we decided that we would come to the US for residency. Family medicine stood out to me for being able to treat patients of all ages with a holistic approach and also being able to work my hands in different procedures. Primary care is broad and I enjoy the variety of possibilities.

In my free time I am a saxophonist, gamer and farmer. I like to play different sports and to be outside with my German Shepherd, Max. I’m excited to be able to be a part of the DeTar family and hope to make a positive impact in the community. Go Cowboys!


Pauline Roxas, M.D.

Dr. Roxas completed her undergraduate and medical training at Dr. Jose P. Rizal School of Medicine – Xavier University, Philippines. Upholding the school’s maxim of becoming a doctor for others, she has directed her career to a specialty that allows flexibility in practice that also extends opportunities to provide holistic care for individuals across all ages and to rehabilitate and support communities.

After returning to the United States to further her medical training, she worked in several clinics for Neurology, Psychiatry, Internal Medicine, and Pain Medicine while working as a guest faculty member of her alma mater during the pandemic. Her experiences strengthened her interest in caring for people with disabilities as she witnessed the transformation of patients who were seen for long-term care. She aims to be involved in the progress of medicine through research and the education of aspiring physicians.

After rotating in DeTar Hospital, she immediately felt at home. She is confident that the program will support her in nurturing the knowledge and skills that she needs to be the physician she envisions herself to be and the leader that her community needs.


Amanda Arauz Tobar, M.D.

I was born and raised in Guatemala City. I studied Medicine at Universidad de San Carlos where I also received a degree in Hospital Administration.

During my middle school and high school years, I was exposed to the Hospital setting and different medical treatments for friends and family which made me fall in love with the idea of being a doctor. Since the beginning of my career, I had the opportunity of offering service in hospital settings, and small communities. I met incredible people that taught and oriented me on my path to Family Medicine.

During these years I was also ablaze after I met my husband who gave me the idea of dreaming big and becoming a medical provider in this fantastic country.

My dream is to become a successful physician that provides medical services in the US and create a non-profit organization in Guatemala that allows me to be thankful for my native country.