About:
John Patrick Mahon (February 2, 1938 - May 3, 2020) was an American film, stage and television actor. He was known for Armageddon (1998), L.A. Confidential (1997) and Zodiac (2007).

• Known For
• 
  A Call to Arms
  as
  Major General Cosgrove USMC
• 
  The Couch Trip
  as
  Police Captain
• 
  A Killing Affair
  as
  Det. Shoup
• 
  Someone's Watching Me!
  as
  Frimsin
• 
  The American President
  as
  Chairman of the Joint Chiefs