J.D. Cannon was a prolific character actor who worked on many shows. He was on the stage, movie screen, and TV. I saw him in theater-in-the-round as the King in the King and I in 1963, and he did a wonderful job. He could also do comedy. Most of his roles involved playing grim, gruff, and/or nasty characters. His gravely voice was well suited to these roles. As Peter B. Clifford he was constantly in a high state of aggravation with Sam McCloud. Apparently he retired from on-screen roles after a Law & Order episode in 1991. His death on May 20, 2005 was not widely reported.