And thats exactly what they do. They find victims that will not fight back. In this case; drunk girl. This is true with every terrorist acts and mass shootings... all soft targets... gun free zones... unarmed civilians.
They will not attack anything that will offer resistance.
I was at the Garland event and they sure met with resistance there. Of course, we attendees inside were disarmed, but there were plenty of cops around that were armed. But you’re right, they pick easy victims.