The FBI's "60 day rule" which suggests any perceived interference in elections be avoided was only "formalized" four years ago by Obama's DOJ head Eric Holder.
From The New Yorker:
Traditionally, the Justice Department has advised prosecutors and law enforcement to avoid any appearance of meddling in the outcome of elections, even if it means holding off on pressing cases. One former senior official recalled that Janet Reno, the Attorney General under Bill Clinton, “completely shut down” the prosecution of a politically sensitive criminal target prior to an election. “She was adamant—anything that could influence the election had to go dark,” the former official said.Read more