Trusted Security Services for Maryland, D.C., and Pennsylvania

Family-owned and led by a seasoned law enforcement professional, Defender One delivers reliable, responsive security—available 24/7 and tailored to your needs.

We Care About Your Safety

Defender One Security delivers trusted, comprehensive security solutions across Maryland, Washington, D.C., and Pennsylvania. Founded in 2009 by Baltimore native Jon Krieger, the company remains proudly family-owned and operated.

With more than 30 years in law enforcement—including leadership roles in patrol, internal affairs, traffic, and community outreach—Jon launched Defender One to bridge the gap between private security and public safety. That same commitment to professionalism, accountability, and community still drives the company today.

As a family-run business, Defender One offers a level of personal service and responsiveness national firms often can’t match. Jon and his wife Jennifer oversee daily operations, working directly with clients to ensure every detail is handled with care and integrity.

Trusted Security Solutions Since 2009

Decades of experience, grounded in law enforcement leadership and a commitment to professionalism you can count on.

Highly Trained Security Professionals

Our team is made up of skilled, vetted experts trained to deliver preventative, site-specific protection.

24/7 Coverage and Peace of Mind

We provide around-the-clock security through contracted services—ensuring consistent presence, not reactive response.

Family-Owned, Personally Committed

We’re not a faceless franchise. Every client matters, and every detail is handled with care by our leadership team.

Don’t leave safety to chance. Work with a team that treats it like a priority—because it is.

Our Comprehensive Security Services

Reliable Security Presence for Your Property

Uniformed security professionals stationed at your facility to deter threats, safeguard property, and ensure a safe environment. Ideal for corporate offices, retail, schools, healthcare facilities, and more.

Executive and Personal Security You Can Trust

Whether you need discreet protection for an event or long-term security for high-profile individuals, our team delivers peace of mind with professionalism and discretion. Transportation services available.

Fast, Professional Fingerprinting for Individuals & Teams

We offer efficient fingerprinting for employment, licensing, compliance, and more. Available for individuals or coordinated group sessions for companies and organizations.

News & Resources

Schools Need Security Drills Beyond Fire Alarms

Schools Need Security Drills Beyond Fire Alarms

Fire drills are a long-standing tradition in schools, ensuring students know how to evacuate safely. However, schools need security drills beyond fire alarms to address modern threats effectively. Schools face risks that range from active threats to medical crises and...

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Protecting Executives from Cyber and Physical Threats

Protecting Executives from Cyber and Physical Threats

A CEO’s influence extends far beyond boardrooms. Their decisions move markets, their visibility invites scrutiny, and their digital footprint exposes vulnerabilities. From cybercriminals seeking financial gain to physical threats like stalking, executives are prime...

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School Security Services for Safer Learning Environments

School Security Services for Safer Learning Environments

Schools should be places where students learn, grow, and build their futures. However, with safety concerns on the rise, creating safer learning environments requires a proactive approach. Implementing school security services helps prevent issues like unauthorized...

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Event Security Services for Safe and Controlled Crowds

Event Security Services for Safe and Controlled Crowds

Large-scale events offer opportunities for entertainment, networking, and celebration. However, managing large crowds comes with security challenges. Without proper planning, even the most well-organized events can become chaotic. Professional event security services...

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Retail Theft Prevention Services for Business Owners

Retail Theft Prevention Services for Business Owners

Retail theft is a growing concern for business owners. Every year, shoplifting, employee theft, and organized retail crime result in billions of dollars in losses. Without proper retail theft prevention services for business owners, businesses risk financial setbacks,...

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