Agree with most, but to play devil's advocate,
The bold, not so sure about that. A LOT of serial killers are not sorry. Richard Kuklinski for one, serial killer turned mafia hitman with over 200 murders on his hand, admits in several interviews (can watch on youtube) that he never felt bad. Felt nothing. The ONLY thing he felt bad about was when his family found out and how it hurt them (the guy managed to keep it secret).
And Hitler killed himself because the alternative was to be captured, NOT because of guilt.