It is NOT justified by the book they claim it's justified in..they are just twisting the words of God to make it seem like it is. I can challenge anyone of em Taliban guys to come and show me where in the Quran it is made permissible to accuse a woman of adultery, then condemn her to death without a fair trial, and shoot her as a means of assassination!
Mandi is right..this has all the makings of a so called honor killing and is cold blooded murder indeed.