Literally

Whitey Bulger was a go-between for The Biden and Ukraine crime families and his own.

He also was the mole who turned over the Italian-American mob because it wasn't globo-homo friendly enough for the Tribesmen.

His incursion into government positions was so big, mobsters were cops and cops, mobsters and neither were sure which was which.

Why was Whitey moved to another prison without cause just to get him killed? (on Halloween)

I answered my own question.

And why so many years after his heyday?

You know who put Mr Untouchable behind bars when others wouldn't touch the case?

Mr. John Durham