Sex in the stationhouse: What’s the relevance?

Joshua Mauldin’s legal problems just got a bit more complicated. After being charged with (and confessing to) microwaving his infant for 10-20 seconds, prosecutors are now seeking to have introduced at trial evidence that he had oral sex with his wife in the interrogation room at the police station.

His defense to the charged crime is insanity in that his acts were the result of hallucinations, which he has suffered from since he was 10. Prosecutors want to introduce the tryst as evidence that he is lucid and does not suffer from hallucinations.

Assistant District Attorney Xochitl Vandiver said jurors should know about the alleged sexual encounter between Mauldin and his wife, Eva Marie Mauldin, because it reflected his state of mind. “That piece of information is relevant to the defendant’s guilt,” Vandiver said.

Relevant how? It reflected his state of mind at the time he received oral sex, but what does that have to do with his state of mind at the time that he microwaved the baby?

Sadly, it seems that the judge might entertain the state’s request:

Judge Susan Criss, presiding over the trial, declined to make a formal ruling Monday on whether the couple’s police-station liaison would be admissible during trial. However, she warned [defense counsel] Cammack that he would need case law to back up any argument that the encounter should be kept from jurors.

Case law? How about the Rules of Evidence, specifically the one dealing with relevance? EvidenceProf has the correct analysis, in my opinion:

‘Relevant evidence’ means evidence having any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence. Now, if defense counsel’s argument was that the defendant was catatonic and never lucid, this evidence could potentially be relevant.  But defense counsel’s claim seems to be that the defendant was usually lucid but that he suffered from occasional hallucinations, one of which allegedly occurred when he injured his daughter.  I don’t see how proving that the defendant was lucid days later when he allegedly had oral sex with his wife, however, is relevant to whether he was hallucinating when he injured his daughter.

I agree. This is nothing but an attempt to portray the defendant as having a bad character – evidence that should be inadmissible, without need for supporting case law. How this is not akin to the widely deplored “slut defense”? In fact, if anything, this is less relevant than subsequent sexual conduct of a victim in a consent case.