You go to the gun store, find the gun you want, and then fill out the paperwork for the background check and pay for it. You do have to wait ten days from the time you buy it to the time you pick it up. But there's none of this business of getting a permit from the police department or anything like that. That doesn't exist there.
They do have an approved firearms list, and anything not on that list you can't buy. My army vet friend who lives there, for example, can't buy a fifth generation Glock like we NJ people can because they're not on the list. Only the third generation Glock is. Also, assault rifles cannot have even one "evil feature." Here you can have one.
However, some counties there are shall-issue for carry permits. Some are not. My friend has a carry permit and he's not a cop or ex-cop or anything like that.
Your biggest concern would be syringes from Kensington washing over your property....
As Glen mentioned, this seems like a very infrequent event. I remember reading news stories about the possibility of this something like 20 or 30 years ago.
How many times has this happened in the last 500 years? I don’t think too many times.