About Us

Sentry Security Agency has been protecting the St. Louis Metropolitan Area for over 50 years.  We provide on-site security officers for both commercial and residential customers. We are a family-owned local business. The Mueller Family, who own and operate Sentry Security, are proud of their heritage which includes three generations of U.S. Marines and three generations of the St. Louis Metropolitan Police Department. Our Directors and Managers have over 20 years experience working directly in the security industry. 

WBE Certified

Sentry Security Agency of St. Louis is proud to announce its WBE Certification.

The St. Louis Airport Authority (SLAA) has declared Sentry Security Agency of St. Louis as a certified Women Business Enterprise (WBE) Company. John and Catherine Mueller, owners of Sentry Security Agency of St. Louis, completed the application and process required to become WBE certified.

Sentry Security Agency of St. Louis has provided Security Guard and Patrol Services for over 50+ years in the greater St. Louis and surrounding areas. The company also began performing corporate employment background screening for many major company's including World Wide Technology, Schnucks, and Steris Corporation.

John Mueller has been with Sentry for 30+ years whereas his wife, Catherine, began taking a much more active role over the past 10 years. Her responsibilities include articulating the mission/purpose of the business; determining its managerial and reporting structure; as well as continuing to manage the financial accountability of the company. Catherine holds a Bachelors’ degree in Business Administration from the University of Missouri - St. Louis with an emphasis in IT.

Becoming WBE Certified marks a significant milestone for Sentry Security Agency of St. Louis as it continues to expand its footprint and enhance its service offerings in the St. Louis region. The company aims to leverage cutting-edge technology and best practices to provide top-tier security solutions to its clients. “I am excited to accept the WBE certification for Sentry Security Agency and lead us into its next phase of growth,” said Cathy, "At this point, we have empowered a new, almost 85%, all women management team to bring Sentry Security to new heights".

Sentry Security Agency of St. Louis is a premier provider of security solutions, dedicated to safeguarding businesses, communities, and individuals.