Our Team
Mario Truman-Villanueva
Founder / CEO
As a veteran and healthcare professional, I believe everyone should have the skills and confidence to act when it matters most. The discipline and leadership I gained through military service, combined with my hands-on healthcare experience, showed me how critical real training and preparation truly are. I founded StoneGuard to bridge the gap between education and real-world readiness, not just to hand out certifications, but to build true competence, courage, and clarity under pressure. StoneGuard exists to empower individuals and organizations to protect, lead, and save lives with purpose, compassion, and unwavering confidence when every second counts.
Keysha Williams
Co-Founder / Chief Of staff
Coming into the healthcare industry with no experience, I quickly learned that the true backbone of any organization is the people who support, train, and provide direct care to the community. They are the ones keeping everything moving, even when they’re not always recognized. My goal is to build systems through our company that empower, properly train, and support these professionals so they can deliver confident, high-quality care while feeling valued and backed every step of the way.