Them forgiving his family is awe inspiring.
Forgiveness that matters to the perp is out of their hands. I assume they are mourning his eternity in hell.
The Amish would be the first to tell you they do not know where Roberts ended up.
I would expect them to forgive the family - they didn't commit the crime. In fact, there's nothing to forgive the family for!
I agree with Christian teachings, but if you want to believe in concepts like "the just war", there comes a time to put forgiveness aside and bring out a little harsh human judgment.
You don't have to stew in hate, but you don't have to be completely passive either. It's OK to think of this gunman and think of him as evil. That's what we do with terrorists. I don't forgive the 9-11 hijackers, nor do I let my hatred of them consume me. I simply think of them as evil and use that thought as a reminder of the evil of which men are capable. Forgive the terrorists? No thanks. I'm happy with the idea that they are burning in Hell. Forgive this gunman? No thanks to that, too.