Oklahoma's Most Trusted Private Investigations Firm

We are a Tulsa-based, full-service detective agency offering investigative and consulting services across the state and country. We have the experience, resources, and tenacity to uncover the truth and deliver results.

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We work in the trenches so you don't have to.

 Let our team of professional investigators deliver the answers you need.

Cullen Investigations is a full-service licensed and bonded private investigations agency based in Tulsa, Oklahoma. We offer a wide array of investigative & consulting services, including domestic relations (custody, infidelity), background checks, crisis management, complex litigation, and criminal defense investigation from pre-filing to post-conviction relief and death row appeals.

Divorce, Infidelity, Custody, Asset Searches

Domestic Relations

Custody Cases
Asset Searches

Pre-charge investigations, pretrial defense, civil & complex litigation, post-conviction relief, appeals from stage one to death penalty

Legal Investigations & Support

Pretrial Defense
Civil & Complex Litigation
Post-conviction Relief

Background checks, due diligence investigations, on-the-job injury


Background Checks
Due Diligence Investigations 
On-the-job injury

Statewide process service, skip trace, missing persons, heir location

Location & Process Service

Statewide Process Service
Skip Trace
Heir Location

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Nationally recognized as one of the most effective agencies in the country.

From left to right: Eric Cullen, Corey Atchison, and Joe Norwood on the day of Atchison's exoneration and release from prison
                                                                                                CREDIT: Mike Simons/Tulsa World
“The fact of private investigator Eric Cullen’s involvement, more than any innate self-corrective mechanism in the judicial system, was the critical factor in these cases. Had he not come along, and had he been less persistent, the men would likely still be incarcerated—and would have remained so until their deaths.”

— Washington Post 2019 editorial, “Two extraordinary exonerations show the failure of our justice system”

Additional Media Coverage

Washington Post logo
NBC logo
Wrongful Conviction with Jason Flom logo
Tulsa World logo

Our Story

The genesis of Cullen Investigations began in 2001, when Eric Cullen’s best friend died senselessly and tragically while in police custody. 

The son of a respected homicide detective, Eric originally thought he would become a cop. But in the wake of his friend’s death, he became acutely aware of the injustices that plague our legal system. He realized he could make a bigger difference on the outside, as a private investigator. In 2005, he founded Cullen Investigations.

Over the next 15 years, the modest agency blossomed into a full-service investigations firm—one of the most respected in the country. Today, Cullen and his team of investigators carry a reputation for delivering measurable results through dedicated, effective, honest work.

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