Background:
My question involves defamation in the state of: WA

Looking to sue FBI and local Sheriff for defamation (1 false crime) discovered
after Concealed carry permit application.

False crime is DV/Gross Mis. "convicted" 6 years ago. From another State that I lived in, county records are on line and correct. No criminal convictions.

WA Sheiriff did FBI NICS check and denies CC permit in shall issue state.

FBI NICS appeal not even looked at. They mailed it back and cited various Brady laws that justify no appeal.

Sent in local appeal, they will just blame FBI and site false record.

Looking to sue both.

Questions: As jurisdiction is very confusing

1: FBI is in District court, but what law applies? Fed, state, both?
2: Can I get Sheiriff in District court under civil rights violation? Or seperate suit in state court for defamation?
3: Should I include gun rights in the case(s)? Or stick with defamation per se?

Thanks in advance!