1. The phone records are facts, and not hearsay. Who did the calling can be inferred.
2. What they spoke about is not hearsay if at least one party to the actual conversation is willing testify and is subject to cross examination. Thus, Turnbull can get on the stand and recount the conversation, but only if Frederick’s lawyer can cross-examine Turnbull to determine truthfulness etc. T

However, it would be hearsay for the police to say what Turnbull told them that Frederick said, if used to prosecute Frederick.

And, it’s more the shame because of how flimsy the police account of this actually sounds. I’ve mentioned before how the prosecutor is pushing a very weak story. The prosecution’s basic narrative here is that Ryan Frederick is so stupid that (remember that this is the prosecution’s allegation) -

* Frederick knew in advance that the police were coming to raid his “grow operation” and that he “had a plan” for them.
* Frederick announced that plan to to people who didn’t like him personally and that he knew to be police informants. (Apparently, letting the police know that he had a plan was part of the plan. Very devious.)
* Frederick cleaned out his alleged grow operation. At this point, all the police had on him was the word of two criminals.
* Frederick is gainfully employed and engaged to be married and there is no evidence that he has a death wish. But, after making sure there was no evidence against him, he planned to lay in wait to engage in a suicidal gunfight with armed police. Nevermind that he was only facing charges for a small-time grow operation that likely couldn’t be proven anyway. And nevermind that a single person pointing a gun at several cops is more dangerous than pointing it at his own head. Even if no one had actually been hurt, it would result in the harshest possible prosecution.
* The police, knowing that he knew they were coming, still carried out their nighttime raid against someone against whom they were likely to find no evidence and who they believe was laying in wait. All that instead of peaceably picking him up en route to work or the grocery store.
* After shooting one cop, Frederick suddenly decides to give up willingly.

If the prosecution’s account were true, Frederick’s lawyer would have a pretty tight case that Frederick lacks mental competence to stand trial, because no one who isn’t an outright moron would execute such a plan.

And, all that is aside from other factors such as inconsistencies in where the police say they were when shots were fired; how little they actually found at the raid; potential evidence tampering at the scene with removed bullet slugs; etc. Add that to the issues of illegal police evidence gathering and warrant issues and Ryan Frederick really should have gotten this case dismissed. It seems certain that, if the people who broke through his door that night had been members of a different group, they would be on trial right now.

I’m not a lawyer, so I don’t know the rules, but on its face it seems to be fairly clearly inadmissible.

Is it really the case that the feds can grant immunity against state prosecution? I had thought federal investigations could only grant immunity against future federal prosecution, but that a federal immunity grant couldn’t bind state or local prosecutors.