S.E.M Security President Stephen Mocarsky has a long history, almost 50 years of experience, in the field of home and business security. What started as a career in fire protection took a turn into the security and alarm sector when Mocarsky experienced a home break-in personally. This ordeal sparked a new interest in the security industry where he could help protect others from similar incidences.

Starting in 1975, he began his journey to becoming an expert in customizable residential and commercial security systems when he took his first alarm system job in the Orange County, NY area. 

From there, he went on to learn many areas of the industry including working for a UL Listed Central Station installation and service company and as a subcontractor for several large regional security companies in the Westchester Country area. 

Through each step of his career in security alarms and systems, he learned valuable lessons about providing high-quality products and exceptional customer service. He has built these lessons into his company today with his commitment to unparalleled safety and customer service. 

In 1987, S.E.M. Security Systems was born.


At S.E.M Security, we understand these challenges and are totally committed to doing what we can to keep you and your family protected during these difficult times.

Company History

S.E.M Security grew and evolved through direct sales to residences, school districts, commercial businesses, local retailers, restaurants, and more. Over the years, S.E.M. Security Systems acquired several other businesses, including King Protection in NY, Shield Security in NJ, High Tech in NJ, Sonia Security in NJ as well as Alarm Techniques in NJ. This further grew our family and impacted the community in a positive way.

As an industry leader, he is proud of his organization’s business growth and pledges to continually learn about security innovations. As a part of this commitment he routinely holds CEU classes as well as training from manufacturers, Fire Alarm Inspection, and testing training to ensure that our service team is prepared to service any application.

Today, Stephen and his team take pride in providing quality installations with the very best products in the industry to meet the needs of their customers, completing installations for both large and small companies to residential systems. The team is among the best in the business, resolving customer issues and keeping systems running smoothly.


  • Alpine
  • Ridgewood
  • Ramsey
  • Mahwah
  • Tenafly
  • Cresskill
  • Englewood
  • Englewood Cliffs
  • Saddle River
  • Franklin Lakes
  • River Edge
  • Haworth
  • Allendale
  • Glen Rock
  • Ho-Ho-Kus
  • Fort Lee
  • Leonia
  • Fair Lawn
  • Ramsey
  • Oradell
  • Waldwick
  • Cliffside Park
  • Hackensack
  • Rutherford
  • Saddle Brook
  • Rochelle Park
  • Bergen Field
  • Paramus
  • Carlstadt
  • Teterboro
  • North Arlington
  • Bogota
  • Ridgefield Park
  • New Milford
  • Palisades Park
  • Oakland
  • Westwood
  • Wood -Ridge
  • Ridgefield
  • Little Ferry
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