How can the feds be involved before it is determined that state lines were crossed or that the bomber is a foreign national? Shouldn’t the state be handling this? Of course, the state can “ask” for federal assistance....
If this is a Reichstag-fire event, then the Feds are involved by definition.
I would think that federal authority comes into play because the ATF handles explosives.
However I have not heard of an immediate federal response to the bomb that was mailed to Sheriff Joe Arpaio last week. Why was Mr. Obama silent on that bit of domestic/international(?) terrorism aimed at law enforcement?