Friel joined the Philadelphia Police Force in 1960 at the age of 18. From 1982 to 1988 he was chief investigator and co-director of the Philadelphia Plice/FBI Organized Crime Task Force in Philadelphia. He was a guest lecturer for the FBI on the problems of organized crime, serves as a consultant to Major League Baseball on organized crime, and teaches courses about organized crime at LaSalle College and St. Joseph and Temple Universities.