FBI agent falsified documents to obtain warrant to spy on opposition candidate. Spying on elected President continued after election.

“If there was an FBI agent sworn to uphold the Constitution who can be proven to have altered the document in connection with a legal proceeding, including the obtaining of a FISA warrant, that’s really serious. It doesn’t get a lot more serious than that,” former U.S. Attorney Preet Bharara said Thursday evening on CNN.

https://www.washingtonexaminer.com/news/fbi-official-under-criminal-investigation-for-altering-document-related-to-carter-page-surveillance