The FBI was caught falsifying documents in the Mueller investigation.

https://www.usatoday.com/story/news/politics/2020/08/19/ex-fbi-lawyer-kevin-clinesmith-court-1st-durham-case-russia/3393941001/

https://www.cbsnews.com/news/former-fbi-lawyer-kevin-clinesmith-pleads-guilty-first-criminal-charge-durham-probe/

https://www.nbcnews.com/politics/justice-department/ex-fbi-lawyer-plead-guilty-falsifying-claim-made-continue-surveillance-n1236767