So who wins the gun debate this time?

Two days since the Navy Yard shootings, and we now know there weren’t three gunmen, or two, but just one, Aaron Alexis, and that he didn’t use an AR-15 assault rifle, according to the FBI.

“We believe that Mr. Alexis entered building 197 with a shotgun,” said an FBI spokesperson at a news conference.

It turns out that when he walked into Sharpshooters Small Arms Range in Lorton, Virginia to buy his murder weapon last Saturday, he actually test fired an AR-15 but bought the shotgun instead.

And had no trouble doing it because his background check was clean as a whistle.

There was some criticism of the Navy for making the Navy Yard a gun-free zone, but there were armed security guards, one of whom was gunned down by the killer – who then took his gun and used it.

After all, as CBS’ John Miller reminded us, he was trained by the Navy – that’s why he opened fire from a balcony: it gave him the tactical advantage.

So what we’re left with is the report that he was hearing voices, and thought microwaves were being fired into his brain, and if you put that and the rest of his records into a giant database, and crank it through some NSA surveillance program you might have enough to put him on a No-Buy list circulated to gun stores – if such a list existed.

But it doesn’t, and so all we have – is the grief of a wife who’s lost a husband. And a daughter who’s lost her dad.

And the questions of so many others who wonder why nothing can ever be done.