“I’ve actually wondered why the FBI inserted themselves in this at all. Isn’t it a Utah issue? Nothing crossing state lines? I’m probably missing something.”
I wondered the same thing. According to several on-line articles, the FBI has broad authority to assist state and local law enforcement. Here’s some examples:
Their was an incident locally some years back that at first didnt seem to have any justification for the FBIs involvement. The long and short of it was that because the internet was involved the crime had “crossed state lines” so wasnt solely local jurisdiction any longer.
If the shooter said anything, coordinated anything, bought something for that event, and did it online then by the “crossing state lines” argument they automatically could be involved.