kingdragonfly:
You would expect criminal investigators to be hush-hush until they've actually laid charges.
As you correctly pointed out, DC is not a state. All felonies committed in DC are federal crimes.
However, the down side is that there's no requirement for charges to have actually been laid for the president to issue a pardon, and there's nothing stopping the president from issuing a blanket pardon to everyone involved in the offence - Jimmy Carter did this in 1977, issuing an unconditional pardon to everyone who dodged the Vietnam War draft.