Welcome to Defender One Security

We Care About
Your Safety.


Defender One Security is a distinguished provider of comprehensive security solutions throughout the Maryland region. We are family owned and operated, led by Jon Krieger, a Baltimore native and the Founder of Defender One who opened the business in 2009 after retiring from Baltimore law enforcement. His primary goal was to bridge the gap between conventional security guards and law enforcement. His long and distinguished career spanned 30 years, holding supervisory positions in several units including patrol, internal affairs, traffic and community outreach. Today his son Jared and his wife Jennifer are running the daily operations.





We protect your members, your clients, your patients, your employees, your loved ones. In this unpredictable world, Defender One protects you from potential threats and unexpected incidences. Together, our people and technology provide the security and protection you need.


Specialized security services encompass a range of focused and tailored security solutions designed to meet specific needs and challenges. These services go beyond general security measures and address unique risks and requirements. The scope of specialized security services can vary depending on the context, industry, and client needs.


We uncover hidden truths. Our private investigation and detective services can provide you with the information you are seeking. From background checks to locating missing persons, corporate investigations, insurance fraud inquiries, asset searches, domestic violence cases, domestic situations, and much more.


Executive protection is a job that requires both tactical and social skills. Defender One understands crowd dynamics and knows how to mitigate any chance of threats. With extensive training in conflict resolution, our team is well-equipped to handle diverse situations and ensure the safety of our clients.


Drawing upon decades of expertise in security, our team of is well-equipped to evaluate your existing security framework, pinpoint potential vulnerabilities, and take proactive measures to minimize security risks.








Deadline - June 1, 2024
$ 200
  • 16 hours for initial security guard training


Required by the State of Maryland
$ 125
  • 8 hours for in-service renewal training


For those who wish to apply for a permit to carry a concealed firearm in Maryland.
$ 375
  • 16 hours for a new permit


Renewal permit classes
$ 225
  • 8 hours in-classroom training


We will custom design a course specific to your needs.


Custom designed for Small Business Owners
$ 500
  • Course focuses on educating your team about responsible alcohol consumption, recognizing signs of alcohol-related issues, and implementing measures to prevent incidents. The goal is to create a safe and healthy work environment while minimizing risks associated with alcohol use.


This program can be customized for small to large businesses.
  • Pricing starting at $750 and increasing based on the size of the program.


It was a pleasure using Defender One for our security needs. They were very professional and punctual. I highly recommend Defender One for ALL your security needs.

Marshall Rief

Defender One is an incredible company to work with. Their security team is professional and pleasant to work with. I have seen members of their team deal with a variety of emergencies and all were handled efficiently and had great outcomes. I feel completely safe working with Defender One and I am so thankful they are here to protect us.

Carly Schwartz Chizuk Amuno Congregation & Schools

Provides excellent, expert services for our organization.

Sandy Nissel CEO // The Bais Yaakov School

I have been employed by Defender One for a year! Without a doubt it’s the best career move of my life! I have read some of the reviews and realize that if you do your job, show up on time and work hard, your experience will be a great one! Hard work pays off with Defender One! Very professionally trained and well treated! Good luck in your search and consider DF1 in your future!

Bill Painter Employee // Defender One

We love Defender One! They always do an excellent and professional job for our organization! Thank you once again for keeping our community and members safe.

Caren Levin Executive Director // BZD


Blogs & News

The Role of Technology in Modern Private Investigations

Essential De-escalation and Active Shooter Response Techniques

Protecting Patients Staff and Assets

Wear & Carry Training: Equip Security Guards with the Right Skills

Securing the Perimeter: Physical Barriers & Access Control

Cynthia Cox

Human Resources Manager

With 21 years of management experience across various industries, including staffing, transportation, small business ownership, accounting, and operations, Cynthia brings a wealth of knowledge and a robust skill set to Defender One. Her diversified background has equipped her with a keen understanding of multiple business domains, making her an invaluable asset to the team.

Matthew Goodman

Assistant Director of Operations
Matt currently serves as Defender One’s Assistant Director of Operations. Matt is responsible for the day-to-day operations of Defender One and works closely with the Director of Operations & Training to implement goals and objectives for the company. As a nationally certified School Resource Officer and Force Science Analyst, Matt brings an interpersonal and holistic approach to the industry. He holds a Bachelor’s Degree in Criminal Justice from York College. Outside of work, Matt is an avid outdoorsmen, spending time perfecting his landscaping skills. Matt also enjoys quality time with his wife Ashley, and two cats, Ollie and Leo, as well as watching the Baltimore Orioles and Ravens.

Jennifer Krieger

Director of Human Resources
Jen currently serves as Defender One’s Director of Human Resources, managing our HR and back end finance teams. Jen has 30 years of experience in healthcare benefits administration, retirement benefits, financial planning and human resources. Jen holds a Bachelor’s Degree in Accounting from the University of Maryland, College Park and a Master’s Degree in Finance from Loyola University. Jen prioritizes an employee focused and driven company, with an emphasis on client and employee satisfaction. Outside of work, Jen enjoys running, watching her daughter play Division 1 Lacrosse, and playing with her grand-dogs.

Jared Krieger

Director of Operations & Training
Jared currently serves as the Director of Operations & Training at Defender One. In this role, Jared is responsible for the overall operations and training of Defender One and its staff. Jared currently holds a Bachelor’s Degree in Homeland Security & Counterterrorism. Jared is board certified in Security Management and Board certified as a Physical Security Processional by the American Society of Industrial Security. Jared is also an accredited Law Enforcement instructor in the following disciplines: Firearms, OC Spray, Expandable Baton, Handcuff, Taser, Defensive Tactics, and Force Science Analytics. Outside of work, Jared enjoys traveling and spending time with his girlfriend and three dogs.

Jon Krieger

Jon is the President and Founder of Defender One. Jon started Defender One in 2009, with the goal of bridging the gap between conventional security guards and law enforcement. Jon had a long and distinguished career in a large metropolitan police department for over 30 years, holding supervisory positions in several units, including patrol, internal affairs, traffic and community outreach. Jon has a Bachelor’s Degree in Criminal Justice from the University of Maryland, College Park. Outside of work, Jon spends his time spoiling his grand-dogs Fred and Barney, supporting the Ravens and Orioles, and watching his daughter play Division 1 Lacrosse.