Not at all, and don't think for a second that you are. I think that you have a good heart and that your intention are pure.
You killed someone //because of work//. Not on your own terms, but because of work (correct me if I'm mistaken though).
Also, you can't let three numbers define you. So you're an 0-8-4 and a danger to others, but have you displayed any signs that you're putting other in danger?
As far as I'm concerned, actions speak louder than words, or in this case numbers. You are not a bad person. I think you're fighting on the right side, for the right people, for the right reasons. You should never think for a second, "I'm a bad person" because in reality, you're not.
Your 0-8-4 status does not define you. It's nothing more than a label.
In short, you are not a bad person. Never, ever think for a second that you are.