The Man Who Killed Hitler and Then The Bigfoot.
Which sounds odder than it is.
Actually a very low key film. Sam Elliot as the slightly misanthropic old man, a bitter recluse, who it turns out, was a semi-mythic solider/assassin for the US in his younger days. You get the slow opening of his daily life, interspersed with short flashbacks which establish his history (Which yes, includes killing Hitler), while background news reports on some serial killer on the US/Canadian border crop up. This leads into government officials turning up to tempt him to return to duty for various reasons to hunt down and kill The Bigfoot, which is apparently infected with some strange disease that if allowed to get into the population could be devastating.
It's an oddly paced film, and it definitely doesn't fit in the action genre. Much more the slow-paced Adventure/Drama area. An old man pondering how his life led him, the love he lost, whether the people he killed ever actually changed anything.