I would record that conversation and send it to the FBI, and if that didn't get any traction, the Press.
I suppose that’s how they continue to get away with it. We’re all hoping someone else falls on their sword.
This is a good tactic in many other situations as well.
extortion is unrelated of the exact words used but the intend
that clever phrasing can make you avoid extortion charges or similar is a common misbelive
if a cop gets away with a clear extortionist behavior it's because the prosecutor lets them and uses formulation as a shallow excuse not because clever formulations protect you from the law