What Is a Private Investigator? A Complete Guide to Investigative Services in Southern California

Have you ever wondered what a private investigator actually does? Or who really hires one? You’re in the right place. This guide answers both questions. It also introduces the investigative services Corinthian Group provides across Southern California. We operate under the license AIR – Agency of Investigation Recon (California PI License #26978), and we serve individuals, attorneys, and businesses alike.

This is the first post in an ongoing series. Each month, we’ll publish a new deep-dive on a specific investigative topic. And we’ll link every future post back to this page, so you’ll always have a home base to start from.

What Is a Private Investigator?

A private investigator, or PI, gathers facts and evidence for a client. That client could be a private individual, an attorney, an insurance carrier, or a business. In California, the Bureau of Security and Investigative Services (BSIS) licenses and regulates every PI. This state agency falls under the Department of Consumer Affairs, and it enforces Business and Professions Code Chapter 11.3.

So how is a licensed PI different from an unlicensed “information broker”? Here’s what sets us apart:

• We pass a state licensing exam and background check
• We follow California law on privacy, surveillance, and evidence handling
• We produce documentation and testimony that holds up in family court, civil court, and criminal proceedings
• We carry professional liability insurance

Before you hire any investigator in California, verify their license first. You can do that instantly through the BSIS online license search. We always encourage clients to check.

Who Hires a Private Investigator? (And Why)

Private investigation isn’t just for divorce cases in old movies. Real people hire us for real reasons. Take a look at our most common clients, the problems they bring us, and the service that solves each one.

Our Core Specialty: Surveillance Investigations

Surveillance is the heart of what we do at Corinthian Group. Maybe you need to document a parent’s undisclosed household. Or confirm a spouse’s activity. Or catch a fraudulent workers’ comp claim on video. In every case, skilled surveillance builds the same thing: clear, time-stamped, court-ready evidence. Learn more on our Surveillance Investigations page.

Child Custody & Cohabitation Investigations

California family courts take custody violations seriously. But only when solid evidence backs up the claim. That’s where we come in. Our child custody and cohabitation surveillance services help parents in Beverly Hills, Cheviot Hills, Manhattan Beach, Malibu, Rancho Santa Fe, La Jolla, and Del Mar. We gather the documented proof your family law attorney needs to petition the court for a custody modification.

Infidelity Investigations

Suspecting infidelity takes a toll. So does not knowing for sure. That’s why we offer discreet, professional infidelity investigation services throughout Southern California’s most affluent communities, including Laguna Beach, Irvine, La Jolla, Del Mar, and Rancho Santa Fe. Discretion matters most here. So does protecting your reputation. We deliver both.

Workers’ Compensation & Insurance Fraud Investigations

Fraudulent workers’ comp claims cost California employers and insurers billions of dollars every year. Our workers’ compensation and insurance fraud investigations give employers, third-party administrators, and insurance defense attorneys the evidence they need to fight back. We proudly serve the Inland Empire and Riverside County, including Corona, Norco, Eastvale, Rancho Cucamonga, Menifee, Murrieta, Temecula, Fallbrook, Canyon Lake, Alessandro Heights, and Canyon Crest.

Aerial Surveillance & Drone Reconnaissance

Here’s what sets us apart from most PI firms: our principal investigator holds an FAA Part 107 Remote Pilot Certificate. That means we can legally fly commercial drones for aerial surveillance and reconnaissance. Why does that matter to you? Large properties, agricultural sites, construction zones, and hard-to-reach vantage points all become accessible. Learn more on our Aerial Surveillance & Drone Reconnaissance page, where we also explain how we support other licensed PI firms that need subcontracted drone coverage. You can also review the FAA’s official Part 107 requirements at faa.gov.

Criminal Defense Investigations

A strong criminal defense needs independent investigation. That means locating and interviewing witnesses. It means documenting the scene. And it means reconstructing the timeline with evidence law enforcement may have missed. For criminal defense investigative support in California, visit our Criminal Defense Investigations page.

Why Work With a BSIS-Licensed, FAA-Certified Investigator

An unlicensed investigator can put your entire case at risk. Evidence gathered illegally, or by someone without a license, may not hold up in court. It could even expose you to liability. Corinthian Group operates under AIR – Agency of Investigation Recon, California PI License #26978, registered with the Bureau of Security and Investigative Services. Before you hire us, or anyone else, verify the license through the BSIS license search.

Want to learn more about the profession? These two independent organizations are great places to start:

• California Association of Licensed Investigators (CALI) — the largest state PI association in the country, with consumer education and a “Find an Investigator” directory
• National Council of Investigation and Security Services (NCISS) — the national association representing licensed investigators before Congress and state legislatures

Our Southern California Service Area

We proudly serve Southern California’s most affluent communities, including:

Los Angeles / Westside: Beverly Hills, Cheviot Hills, Manhattan Beach, Malibu Orange County: Laguna Beach, Irvine San Diego County: La Jolla, Del Mar, Rancho Santa Fe, Fallbrook Inland Empire / Riverside County: Corona, Norco, Eastvale, Rancho Cucamonga, Canyon Lake, Murrieta, Temecula, Menifee, Alessandro Heights, Canyon Crest

Frequently Asked Questions

What can a private investigator legally do in California? A licensed PI can watch and document activity from public locations. We can also review public records and interview willing witnesses. Then we compile everything into documentation for legal proceedings, always within California privacy law.

Is surveillance footage admissible in family court? Often, yes. California family courts regularly admit surveillance evidence when a licensed investigator documents it properly. That said, admissibility depends on how we obtained it and how your attorney presents it. So always loop in your family law attorney early.

How much does a private investigator cost? It depends. Case type, duration, and whether you need aerial support all affect the price. Most surveillance investigations run on an hourly rate plus a retainer. Contact us for a quote based on your specific case.

Do you work with attorneys and other investigation firms? Yes, often. We regularly support family law attorneys, criminal defense attorneys, and insurance defense counsel. We also partner with other licensed PI agencies that need subcontracted surveillance or FAA-certified drone coverage.

Get Started

Are you facing a custody dispute? Do you suspect infidelity? Are you managing a questionable workers’ comp claim? Or do you simply need aerial documentation? Either way, Corinthian Group can help. We work discreetly, legally, and deliver evidence that stands up. Contact us today to discuss your case confidentially.

Corinthian Group is a registered trade name of AIR – Agency of Investigation Recon, California PI License #26978, licensed by the Bureau of Security and Investigative Services. Our principal investigator also holds an FAA Part 107 Remote Pilot Certificate.