Suddenly (1954)

What it's about

The tranquility of a small town is marred only by sheriff Tod Shaw's unsuccessful courtship of widow Ellen Benson, a pacifist who can't abide guns and those who use them. But violence descends on Ellen's household willy-nilly when the U.S. President passes through town... and slightly psycho hired assassin John Baron finds the Benson home ideal for an ambush.