Company lists · Data refreshed September 2026
Top 25 Investigator recruitment services based in the United States
RevenueBase identified 1,192 investigator recruitment services headquartered in the United States as of September 2026 and tracks 15,939 professional contacts across them, including 2,088 with verified work emails. New York is the largest hub.
This list covers investigator recruitment services headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 28, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest investigator recruitment services based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 981 contacts → | ||||
Indirect evidence “US Security Association Inc is a law enforcement company based out of 2914 E 32nd St, Joplin, Missouri, United States.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 2 | 677 contacts → | ||||
Partial evidence “OMNIPLEX World Services Corporation is a leader and innovator in delivering professional background investigations, intelligence support, and physical security services to…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 3 | 626 contacts → | ||||
Partial evidence “Professional Security Consultants, Inc.(PSC) is a world-class provider of security guard services, patrol, investigations, backgrounds, consulting, security screening & specialty…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 4 | 572 contacts → | ||||
Partial evidence “DK Security is unique in that it offers a single company for a wide ranging availability of security and investigative services.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 5 | 511 contacts → | ||||
Partial evidence “Founded in 1982, Ranger American is a professional security organization with an extensive background in the security and investigation fields.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 6 | 404 contacts → | ||||
Partial evidence “American Security & Investigations has provided security and investigative services throughout the upper midwest since 1959.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 7 | 327 contacts → | ||||
Partial evidence “DigiStream Investigations is a full-service private investigation firm specializing in insurance defense and legal support services.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 8 | 252 contacts → | ||||
Partial evidence “ADC supports government and corporate clients with two primary services - personnel security, ranging from pre-employment checks to comprehensive background investigations and…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 9 | 214 contacts → | ||||
Partial evidence “Frasco has hundreds of investigators and regional offices located throughout the country.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 10 | 211 contacts → | ||||
Indirect evidence “St.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 11 | 172 contacts → | ||||
Indirect evidence “ASP is a premium contract security services company based in Northern Virginia and a wholly owned subsidiary of SecurAmerica.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 12 | 164 contacts → | ||||
Indirect evidence “Anderson Security is a 23 year old, locally women-owned (National Women's Business Enterprise Certification) and operated security company that provides security officers…” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 13 | 129 contacts → | ||||
Partial evidence “Beau Dietl & Associates is a premier private investigation firm based in New York City with offices in New Jersey, Florida, and California.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 14 | 107 contacts → | ||||
Partial evidence “Alias Intelligence is a leading background investigations and due diligence company delivering the information and insights our clients need to grow and navigate their businesses.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 15 | 97 contacts → | ||||
Indirect evidence “As we celebrate our 59th year in business, The Richmond Group USA (TRG) has built its reputation as one of the nation’s most established and successful recruiting firms.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 16 | 91 contacts → | ||||
Indirect evidence “Black Box Security Inc.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 17 | 89 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 18 | 88 contacts → | ||||
Partial evidence “Biopharma Informatic is a Clinical Research Investigator Network which provides clinical trial management for interested Physicians, Medical Practices and Health Care Organization.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 19 | 84 contacts → | ||||
Partial evidence “Horsemen Investigations is a full service investigation company, specializing in investigating insurance fraud and in minimizing risk exposure.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 20 | 82 contacts → | ||||
Indirect evidence “AJ Squared Security, Inc.(AJ2), is a privately owned security organization founded in May 2003 and incorporated in November 2003.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 21 | 72 contacts → | ||||
Indirect evidence “Integrated Security Services, Inc.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 22 | 68 contacts → | ||||
Indirect evidence “Hiring the right people isn’t just about checking a box-it’s about ensuring accuracy, mitigating risk, and protecting your organization.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 23 | 68 contacts → | ||||
Indirect evidence “At CITY SAFE PARTNERS SECURITY, we create solutions and put systems in place to ensure that people and businesses are secure.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 24 | 66 contacts → | ||||
Indirect evidence “Century Protective Services is a full service corporate and personal security firm headquartered in White Plains, New York serving the tri-state area.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
| 25 | 66 contacts → | ||||
Indirect evidence “Protective Force International (PFI) is a fully licensed and insured security contracting firm headquartered in Las Vegas, Nevada.” Source: RevenueBase Database · checked Sep 28, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: investigator recruitment services. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names investigator recruitment services.
- Partial evidence
- Its own public description names part of investigator recruitment services, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name investigator recruitment services. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 1,192 investigator recruitment services based in the United States
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Investigator recruitment services based in the United States at a glance
As of Sep 28, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 1,192 companies.
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among investigator recruitment services, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in the United States whose own description of what they do matches “investigator recruitment services”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names investigator recruitment services), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among investigator recruitment services, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 2,088 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 28, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Investigator recruitment services by metro
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names investigator recruitment services, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many investigator recruitment services are there based in the United States?
RevenueBase identified 1,192 investigator recruitment services headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
US Security Association INC, headquartered in Joplin, tops this list with the largest team on record.
Which city has the most investigator recruitment services?
New York leads with 30 headquartered companies, followed by Houston (28) and Chicago (22).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 2,088 verified decision-maker contacts tracked across these 1,192 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 28, 2026.
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Investigator recruitment services by geography
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- Investigator recruitment services based in Australia
- Investigator recruitment services based in Canada
- Investigator recruitment services based in the United Kingdom
About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.
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