Thomas F. O'Donnell is one of seven sons born to Charles and Ellen (O'Boyle) O'Donnell, who were born in County Mayo and immgrated to Poughkeepsie, N.Y.
O'Donnell began his career in government in the U.S. Air Force where he served as a cryptographic linguist for four years. During his Air Force tenure, he attended a year-long program at the Defense Language Institute specializing in German and Russian. He also worked for the U.S. Navy as a civilian contract specialist. O'Donnell joined the Department of Health and Human Services, Office of Inspector General, Office of Investigations in 1997 as a Special Agent in the Los Angeles regional office. In 2002, he was promoted to an Assistant Special Agent in Charge in the Boston regional office, where he has been involved in many major and successful investigations. In 2009, he was promoted to Special Agent in Charge for the New York Regional Office.
