One, a young boy under the influence of a bigger and stronger sibling that can easily manipulate
the younger, less sure of himself, more apt to follow, and not lead.
Emulating what he would perceive as love, as wrong as it is, willing to do anything to impress, and be accepted. Many of us have experienced these same dynamics by siblings bent on molding your ideologies to conform to theirs.
Add to this the distrust, and cynicism by the parents, and you have a perfect storm for terrorists narratives.
I sincerely hope that this young man is apprehended alive, so we can get to the bottom
of this horrible tragedy. Make no mistake, both are guilty, and need to be punished severely!