I would assume they let them go through because they wanted to see where they were going or who was going to meet them. Since I have had a tiny pen-knife with a 1 1/2” blade taken away from me, I don’t see how they could have let them through with the “large knives” unless it was a set-up to catch the people at the other end.
Unless the screener was in on it with them...
“I would assume they let them go through because they wanted to see where they were going...”
LOL, Holland, LOL
You can have large knives in checked luggage. I do it all the time.
Nevertheless, it was criminally wrong, for it made all the innocent passengers unknowing guinea pigs, and potential hostages or casualties.
That's what I was thinking... they've got everything they need except the fluid , the TATP. Letting them get on a flight might be a way of finding out if others on board - or on their next flight if there was to be one- were going to meet them onboard with the fluid, say, in contact lens solution bottles or souvenir snowglobes, etc. If the airports are monitoring by volume the terrorists might need to meet up with a few others to get enough explosive on board.
Maybe they wouldn’t need explosives at all if they’ve got the knives and a fake bomb. Given the number of knives & cutters they may have intended to meet up with another conspirator or two and take the plane over by going after the crew - one or two sudden, bloody kills to frighten passengers , or a threat to slice a stewardesses’ throat & this might make passengers freeze up long enough to wave the fake bomb in their faces to get everyone to remain seated for good, instead of rushing the hijackers to beating the snot out of them. Maybe the perps hoped it would give them time to work on the cockpit door.
The "large knives" were in the guy's CHECKED LUGGAGE, which is the same place you put your small blade knife if you want it to arrive at your destination.