The Outer Limits (1963-1965)
Season 02: Episode 01
"Soldier"
From IMDB.com:
"A soldier from the far future is accidentally teleported back to 1964. The psychiatrist assigned to examine the soldier realizes that he has been bred purely as a killing machine, but he believe he can reawaken the warrior's humanity. Meanwhile, a second soldier arrives, dedicated to hunting and killing his enemy."
"A soldier from the far future is accidentally teleported back to 1964. The psychiatrist assigned to examine the soldier realizes that he has been bred purely as a killing machine, but he believe he can reawaken the warrior's humanity. Meanwhile, a second soldier arrives, dedicated to hunting and killing his enemy."