36 leading Security and Investigations companies in California (2026 list)

The Security and Investigations companies in California listed here are primarily mid-sized to large firms, many with national or international operations. They offer a broad spectrum of services, from physical security and executive protection to advanced security screening solutions and integrated systems. Companies like Inter-Con Security provide comprehensive security services to government agencies and businesses, while Rapiscan Systems specializes in threat detection products.

A notable pattern among these companies is their concentration in Southern California, particularly in the Los Angeles metropolitan area. For example, Security Industry Specialists, AGS Protect, and Professional Security Consultants, Inc. are all headquartered in or near Los Angeles. This regional clustering suggests a significant hub for security and investigations expertise in the area.

#	Company	Industry	Headquarters	Employees	Founded
1	Inter-Con Security icsecurity.com A multinational private security company providing comprehensive security services, risk analysis, and management to government agencies, businesses, and individuals globally	Security and Investigations	🇺🇸 Pasadena	5,126	1973
2	Universal Services of America aus.com A leading security services company formed from the merger of AlliedBarton Security Services and Universal Services of America in 2016	Security and Investigations	🇺🇸 Santa Ana	3,076	n/a
3	Security Industry Specialists sis.us Leader in security services for Fortune 500 companies, international events, and celebrities Known for innovative solutions, transparent approach, and unique corporate culture	Security and Investigations	🇺🇸 Culver City	2,654	1999
4	Rapiscan Systems rapiscansystems.com A global leader in security screening solutions, providing cutting-edge products and services for threat detection and operational efficiency worldwide	Security and Investigations	🇺🇸 Torrance	1,472	1993
5	Andrews International andrewsinternational.com A global security company with expertise in government services, consulting, investigations, and specialized security solutions through strategic partnerships and experienced professionals	Security and Investigations	🇺🇸 Burbank	1,082	1988
6	American Guard Services, Inc.americanguardservices.com An accredited security protection firm specializing in Cruise Ship Passenger Terminal Operations, with nationwide locations and a focus on training staff in industry regulations	Security and Investigations	🇺🇸 Gardena	867	1997
7	Professional Security Consultants, Inc.pscsite.com Provider of security guard services, patrol, investigations, executive protection, and web-based incident management software with national and international operations	Security and Investigations	🇺🇸 Los Angeles	846	1985
8	Bay Alarm Company bayalarm.com A family-owned national security company with a focus on customer safety, employee development, community involvement, and delivering the best service possible	Security and Investigations	🇺🇸 Concord	844	1946
9	AGS Protect agsprotect.com A reliable security guard service known for quality, efficiency, and professionalism Dedicated team exceeding expectations to ensure full satisfaction	Security and Investigations	🇺🇸 Culver City	573	2017
10	Elite Security & Staffing elitesecuritystaffing.com Company provides customized security solutions and nationwide deployment of security guards for events, facilities, and various industries with a focus on safety and satisfaction	Security and Investigations	🇺🇸 San Diego	480	1995
11	Pelco pelco.com This company specializes in developing and manufacturing open IP video security systems, cameras, video management systems, displays, and accessories with high customer service	Security and Investigations	🇺🇸 Fresno	452	n/a
12	Pavion, Formerly RFI pavion.com A leading security integrator specializing in design, installation, and maintenance of integrated systems for various industries, providing 24x7 monitoring and managed services	Security and Investigations	🇺🇸 San Jose	406	1979
13	United Security Services unitedweguard.com Leading security consulting company providing strategic onsite security solutions with professional guard and patrol services, utilizing sophisticated technology for a safe environment	Security and Investigations	🇺🇸 Corona	404	1999
14	Security Guard App securityguard.app The company offers a Security Guard Web App and Mobile App for guards, security guard companies, and clients to manage security operations	Security and Investigations	🇺🇸 San Jose	332	2018
15	GSG Protective Services gsgprotective.com A full-service provider of quality security services specializing in investigations, physical security, technology, training, and consulting for various sectors and environments	Security and Investigations	🇺🇸 Lawndale	325	2000
16	Guardian Security guardian-security.net Provider of security alarm systems and CCTV surveillance camera systems for homes and businesses in Southern California, with value pricing, quality service, and timely installation	Security and Investigations	🇺🇸 Los Angeles	316	n/a
17	Surefox North America surefox.com We specialize in providing custom security solutions with a focus on supporting military veterans and seamlessly integrating into our clients' lives	Security and Investigations	🇺🇸 Sunnyvale	315	2016
18	NAVCO navco.com A national electronic security integrator offering video recording, alarms, biometric identification, access control, system design, remote monitoring, and equipment rental services	Security and Investigations	🇺🇸 Orange	307	1971
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19	Northland Controls northlandcontrols.com Global physical security systems integrator specializing in design, installation, and management for demanding organizations worldwide, driven by core values and operational expertise	Security and Investigations	🇺🇸 Fremont	284	1982
20	C.I. Security Services (CISS)cisssecurity.business.site A security company based in California, offering premium security services for commercial and private properties as well as event security with a skilled team	Security and Investigations	🇺🇸 Glendale	202	1992
21	Skyline Smart Home skylinesecurity.com A leading distribution channel for Brinks Home Security, offering national sales and installations of security and smart home solutions	Security and Investigations	🇺🇸 Downey	183	1999
22	Platinum Security Inc.platinumsecurity.com A customer-focused security company with over 20 years of experience, offering tailored security programs for Fortune 500 companies to homeowners' associations	Security and Investigations	🇺🇸 Los Angeles	182	1997
23	Absolute International Security absolutesecurityintl.com Absolute Security International provides licensed private security services, surveillance, training, threat assessment, investigation, and mediation with over 115 years of industry experience in Southern California	Security and Investigations	🇺🇸 Irwindale	175	2008
24	Superior Protection Services superiorprotect.com Join our exceptional team to be a part of something great	Security and Investigations	🇺🇸 Commerce	161	1994
25	SSD Alarm ssdalarm.com A family-owned security and fire alarm company founded in 1968, offering advanced system solutions, UL listed monitoring, and industry-leading products/services	Security and Investigations	🇺🇸 Anaheim	160	n/a
26	Hikvision USA hikvision.com A global leader in security technology, offering a wide range of products and solutions for various industries with a focus on quality, safety, and cybersecurity	Security and Investigations	🇺🇸 Industry	158	2001
27	ZBeta, Inc.zbeta.com A top-tier firm specializing in strategic physical security design and managed services, aimed at transforming security into organizational excellence	Security and Investigations	🇺🇸 Larkspur	157	2006
28	AmeriGuard Security Services, Inc.ameriguardsecurity.com A Fresno-based private security contractor offering armed/unarmed officers, vehicle patrols, alarm response, security camera installation, background checks, LiveScan fingerprinting, and more nationwide	Security and Investigations	🇺🇸 Fresno	154	2000
29	MPS Security & Protection security-mps.com A full-service security provider offering executive protection, residential security, access control, security patrols, loss prevention, fraud detection, and risk management services	Security and Investigations	🇺🇸 Murrieta	152	2003
30	Off Duty Officers, Inc.offdutyofficers.com National security services provider specializing in off-duty law enforcement officers for workplace violence, executive protection, event security, and various other security needs	Security and Investigations	🇺🇸 Vista	152	1993
31	Alias Intelligence aliasintelligence.com A leading background investigations and due diligence company, offering comprehensive checks, asset searches, and business investigations to evaluate relationships, opportunities, and risk	Security and Investigations	🇺🇸 Los Angeles	149	2021
32	Alvarado alvaradomfg.com A US-based company specializing in secured entry control, admission systems, queuing, and asset protection products, known for quality, reliability, and innovation	Security and Investigations	🇺🇸 Chino	147	1956
33	Spintly spintly.com Company providing easy and secure entry to modern workplaces with a smart access control system using smartphones, eliminating the need for wired infrastructure	Security and Investigations	🇺🇸 Milpitas	146	2018
34	TechReal Capital techrealcapital.com Investment advisor registered with SEC, offering advisory services Past performance not indicative of future returns Investing involves risk	Security and Investigations	🇺🇸 Sacramento	17	2018
35	VAMO Digital vamodigital.com A digital agency empowering professionals to boost profits with innovative solutions since 2010, combining tech and human expertise for growth	Security and Investigations	🇺🇸 Gold River	7	2010
36	ApolloShield Counter-Drone Systems apolloshield.com Specializing in detecting and blocking unwanted drone intrusions, tracking down and arresting unauthorized operators, serving 25+ countries with expertise from Israel Defense Forces	Security and Investigations	🇺🇸 Palo Alto	4	2015

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How this list is built

Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 14, 2026.

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36 leading Security and Investigations companies in California

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