I am not a pacifist, I can't say no war was ever justified, but I am agains violence because it brings pain, just a lot of pain. I am hardly the right person to speak of how conflicts and differences should be resolved, if I knew how I would waste no time and tell the world how to do it.
Still, when people dies like this, anywhere in the world, it even makes ME want to get into an MI-24 Hind and begin to throw fire into the terrorists.
If you ask me, avoid violence, it is painful, and unless you like pain you should have nothing to do with it.
I also understand that there are greater forces that lead us to into violence and make us forget about the pain we make to others, but I still can't find a justification for this, therefor I must assume this kind of violence is not justified, at least not for me, in any way.
I don't know of how much help it can be, particulary coming from a guy who you had probably read no more than a couple of his posts in this forum, but I want you to know that I am, as others here also posted, sorry to hear about your loss.
I don't know what effect my post will have, but I hope is not a bad one. Feel free to completely ignore it if you want to.