Possible Clues:

• 'Gunsmoke' marshal
• "There's Something About Mary" actor Matt
• "Gunsmoke" marshal
• Matt --, character played by James Arness in the TV western series 'Gunsmoke'
• Matt of 'Going in Style'
• Matt of 'Wayward Pines'
• Matt who played a grunge rocker in "Singles"
• Arness TV role
• Hugh of Headstones
• TV marshal who frequents the Long Branch Saloon