Dr. Joseph F. O’Brien, Ph.D.

Dr. Joseph F. O’Brien, PhD is a New York Times bestselling author, U.S. Attorney General’s Award recipient, and one of the most decorated agents in FBI history. Best known as the lead investigator in the case against Paul Castellano, the notorious head of the Gambino crime family, Dr. O’Brien played a pivotal role in the 1985 Mafia Commission Trial, which led to the historic convictions of New York’s Five Families under the RICO statute. His groundbreaking work is chronicled in "Boss of Bosses: The Fall of the Godfather," considered one of the definitive accounts of the American Mafia takedown.

After retiring from the Bureau, Dr. O’Brien earned his doctorate in criminal justice, with a dissertation focused on the roots and reach of Islamic terrorism. He has since worked globally as a licensed private investigator and independent counterterrorism specialist, investigating high-stakes international cases and intelligence failures. His work has taken him from the front lines of mob warfare to the shadowy realm of rogue state actors and jihadist operatives.

Dr. O’Brien is the founder of the Iran Accountability Initiative (IAI), a nonprofit dedicated to exposing and countering terrorism and state-sponsored violence. He is currently writing his second book—a revelatory non-fiction exposé co-authored with American jihadist Dawud Salahuddin, recorded before the terrorist’s death in 2025. The book reveals chilling details of a decades-long U.S. government cover-up surrounding Iran’s assassination of a dissident on American soil and implicates top officials in one of the most egregious national security failures in modern history.

Today, Dr. O’Brien is a sought-after public speaker and expert commentator on organized crime, terrorism, national security, and FBI history. His voice carries the rare weight of lived experience, and his story offers a sobering and timely perspective on the intersection of justice, politics, and power in America.