One of the terrorist scum lived in the area, probably knew the routine of who would enter the temple and at what time..its a very ultra orthodox area, especially early in the morning is when most come to pray
It wasn’t a Sabbath or religious holiday either AFAIK so there wouldn’t be ritual reasons for forgoing the bearing of arms or getting a gentile service to guard them. I hope all Jewish congregations in the area take heed, and it would be very classy if Christians came out to help their Jewish neighbors’ security if it is lacking.