No mention of how they determined it was a girl who carried it. Perhaps the station was on closed circuit monitoring. If she was one of those kidnapped it is possible she was carrying without knowing what was in the bag. That would make all this all the more evil.
Same thought. Using the kidnapped girls. Hell unknowing or even brainwashed by now, who can say? I think it’s more likely than not. Why send one of their own believers when then can send a child who means nothing to those savages.