So in your opinion, we should wait until someone is involved in criminal act and not prevent it from happening. Owning an AK-47 can not be considered an immature task; if it can be, this immature person would also not think of killing 100s of people and even after that would say as being in 30s, I was immature. Come on, give it up; it is a serious crime.
I would not want every person in this country to start owning an AK-47 to protect their family. (owning a revolver or a small weapon can still be considered as an excuse; but owning an AK-47 to protect family is a bullshit argument) That would do nothing but bring this country on the path Afghanistan or Pakistan is going on.