Harvard lawprof Noah Feldman says Robert Durst's confession is not admissible.

What we have is video of Durst, alone and looking into a mirror and saying "What the hell did I do? Killed them all, of course." Feldman says he's "going deeply into the law" and "the circumstances of the statement" and encountering a "profound question about fantasy versus reality, the nature of a soliloquy, and the fascinating human strangeness unleashed by the era of reality television." All of that creates opportunities for presenting other evidence and making arguments about the meaning and weight of the words spoken by Durst, but it's not hearsay, because statements of a party offered by an opposing party are defined by the rules of evidence as not hearsay. [ADDED: Under some states' evidence rules, the statement of a party is hearsay but would fall within an exception to the rule against hearsay.] So what is Feldman's argument?

Then there’s the hearsay rule. It says that statements made out of court are generally not admitted to prove the content of the statement made. A recorded confession must therefore be admitted in under [sic] an exception to the hearsay rule — for example, the exception made for a statement against someone's own interest.

Feldman needs to go a little more deeply into the law! There is obviously no hearsay problem. Feldman goes on to assume that the nonexistent hearsay problem could be overcome and suggests some admittedly weak arguments:

If I were Durst’s lawyer, I would try to argue that producers of “The Jinx” became agents of law enforcement, and from there try to argue that Durst should’ve been given Miranda warnings. But this argument doesn’t seem likely to win, because Durst wasn’t in custody. He was free to leave at any time, and was a voluntary participant in the interviews. It follows that no one needed to read him his rights, even if the producers had become part of the legal apparatus.

Another creative argument I’d advance on Durst’s behalf is that if the producers had become law enforcement, then they would need a warrant to record Durst in the bathroom, because he has a constitutional right not to be recorded where he has a reasonable expectation of privacy. If you don’t have that privacy in the can, where do you? But this argument, too, should fail -- because Durst was wearing the microphone himself. I seriously doubt you have a reasonable expectation of privacy when you’re mic’d up, even in the bathroom.

Then there's the usual fallback argument:

Even if all these legal principles for admissibility are satisfied, the trial judge still must decide whether the evidence to be admitted is more probative than prejudicial. In other words, the judge will ask whether the jury would be more likely to glean useful information from the statement that would help prove guilt or innocence, or more likely to form an irrational prejudice the basis [sic] of the evidence.

In this case, an intelligent judge would certainly conclude that Durst’s statement would create irreversible prejudice in the mind of the jury -- without a reliable basis for proving the truth.

What a strangely extreme statement! First, the rule requires that the prejudicial effect substantially outweigh probative value of the evidence, not just whether the evidence is more probative than prejudicial. What irrational value to the evidence is there that can't be addressed and explained at trial?

Durst’s statement takes the classic form of a soliloquy. And soliloquies are by their very nature ambiguous -- because there’s no actual addressee. We don’t need to communicate with ourselves in spoken words, because we already know what we know. When we talk out loud to ourselves, we’re doing something different: exploring our ideas, fantasies, doubts, fears.

And that's what Durst's lawyers can explain and speculate about to the jury. Talking to yourself in the mirror may be dramatic — I'm thinking of Robert DeNiro in "Raging Bull" (not to mention "Taxi Driver") — but it's not much different from a diary entry? Do I tell the truth when I'm the only one here — as DeNiro famously said — or do I fantasize and lie and puff? Statements have some unknown connection to the truth of the matter asserted — which is the reason for the hearsay rule (and its exceptions) — but there are truth defects in statements made when you are talking to somebody else too. If Feldman's musings were taken seriously, what statements could be heard at trial?

Even the question-and-answer form (“What the hell did I do? Killed them all, of course”) is reminiscent of the untrustworthy soliloquies delivered by Hamlet. 

Feldman speaks of "Hamlet," but I'll reference "Taxi Driver" again. "Are you talkin' to me? Well, I'm the only one here." When you talk to yourself in the mirror, you may get into a frame of mind where you're practicing for or reliving an encounter with another person. Is there ambiguity? Sure. Does that make the evidence inadmissible? Of course not!