I would dare to suggest, that those people were left unmolested as future "government assets".
For what it's worth, I had heard several accounts from random people that were either present or knew someone that was present at the gun store at which Ghamil Gharbi (aka Marc Lapine) purchased the Mini 14.
According to them, Gharbi was acting really strange...to the point where a store employee called the cops, only to be told to sell him the rifle anyway.