So... His Orangeness has been indicted

[hazard]

Across State Lines? Does that bring in the G-Men?

Not wanted in this case. Convictions of Georgia laws cannot be pardoned by the President of the USA.

Yes, it can bring in the federal government. Remember that aside some specific exceptions, federal charges are basically 'did something illegal to federal properties or agents, or the crime crosses state lines'. Should a crime happen in multiple states, multiple states might have their own, unique, charges to add to the matter but it might devolve into an utter shitfest of a jurisdiction dispute, but none of those charges are 'superior' to anybody else's.

And that includes the federal charges. We might see the federal government bring its own charges after Trump has been convicted and sentenced in Georgia, for example.

I know that people generally consider federal charges to be 'heavier', but the reality is that is only because after a conviction in federal court, it is very rare for a state government to decide that they want to tack on their charges because it seems excessively punishing, and the federal government is generally pretty pushy about trying federal charges before state charges.