Turnbull aka "the Professor" - Originally thought to be a member of Senator Geary's staff, but in actuality he was the American Consigliere to the Corleone family. His insights and evaluations were key to the success of many of the Corleone ventures into several legitimate businesses. His only venture into the world of crime was his alleged planting of the gun behind the toilet tank at Louis restaurant. After a very successful career as a consultant to Bernard Kerik, Chief of Police, NYPD he has retired to the Southwest where he is writing novels under the pen name of Mark Winegardner.