I agree with you...there are factors about this criminal's life that I don't and will never fully understand. the circumstances regarding the decisions he made that day, and I agree with you, will never be fully understood. And I don't think, with my confusion over the subject, that i'll even be able to touch the legality of all of this.
I am fully behind self-defense, and the right for others to do so. But in regards to what's happened here, I don't think i'll ever get close to wrapping this around legislation of any kind.
If it were up to me, I would've shot him immediately after he drew his weapon.