what is the title of this movie?

a man goes to prison for a crime that his friend was guilty of and the friend did not come forward to clear him. after a long prison stay he writes and asks "is it better to have loved and lost or never to have loved at all" then proceeds to kill the friends family that he has made while the other was in prison, wife kids,grand kids. making them all look like accidental deaths.
at the end the man begs to be killed to end his suffering and he throws him a gun with no bullets telling him to do it himself.