I believe they had a different or a string of targets planned. The guy murderer picked a fight with the Jewish victim just to use that as an excuse for going there. No way in hell it was just these two acting alone.
I am wondering who his associates were. Wonder if it is possible for LEO to figure out who was visiting the lovely new American family. Also, whats with the cuts or gashes in the walls? Did this peaceful, devout man have a rage problem at home with his sweet bride?