I'VE been "interviewed" by the FBI and there were no recorders and it was all very chummy chummy friendly, only to have it backfire on me.
I think they just like to get information they can use to frame a situation the way they want it to present to a prosecutor for HIM to prosecute .... not the FBI .... they just gather data.
I don't know about the FBI, but state and local police almost always have their interview rooms bugged. You don't see the recorders, but they are there.
That's something every citizen should be aware of.
I was visited by the FBI once on an :Interview” regarding semiconductor price fixing. They started out all chummy. I wrote them a note before I said anything. It said:
Got a warrant?
I want my lawyer.
Didn’t answer any questions. They followed me for days and then just went away.