MMDad
Lem Putt
Google and an evening of practice.. He could tear it all the way down, and put it back together in less than 10-15 minutes.. and really who knows how much time he had or how much time he took to piece it together.
I mean I think that is the thought, he snuck it into the mall broken down in his backpack.. but you could also cut down the stock and the barrel and that would fit in a backpack without any tear down..
Just take off the 18 1/2" barrel, unscrew the stock and put on a pistol grip. Would fit in a backpack and put it together in 2 minutes if you're uncoordinated.