James MacArthur

James Gordon MacArthur (born December 8, 1937 in Los Angeles, California) is an American actor. James MacArthur is best known for the role of Dan "Danno" Williams, reliable second-in-command to Steve McGarrett (played by Jack Lord), head of the fictional Hawaiian State Police squad Hawaii Five-O. The role won him fans all over the world.
See more at Wikipedia.org...