[Hellion]

Very possibly, the FBI has some strong leads, and are building a case.

This is something on the national scale with lots of federal internal attention - reports likely even having hit the potus desk.

I doubt we’ll hear much about this again unless there’s an arrest.

[LarryMullins]

Criminal conspiracy is a real sort of thing that actually happens. There's nothing wrong with speculating about such circumstances. If anything, I think hypothesizing that it was a lone wolf attack is more zany, given similar attacks being carried out in other areas.

[hgsgm]

What do you mean? Law enforcement doesn't comment on details of an investigation except when asking for help finding suspects. If they have suspects they have to investigate quietly until they have enough evidence for an arrest.