Sometimes legal manuevers are too clever by half. The Colorado Court of Apppeals case of the People v. Jimmy J. Vasquez is such a case.
Generally, testimony can't be introduced at a trial unless the witness is subject to cross-examination, due to a part of the constitution known as the confrontation clause and a rule of evidence known as the hearsay rule. Evidence that would ordinarily be barred by this rule was admitted in his case, and because of that, he wanted his conviction thrown out. And, everyone agrees that the evidence that could have been excluded was central to his conviction. On its face, then, this sounds like a perfectly normal and well founded appeal.
But, every rule has its limits.
When your own argument admits that the reason that a witness is unavailable to testify is that you killed her, the confrontation clause is no longer effective to exclude evidence, nor is the hearsay rule, even when you can show that your motive in killing the witness was not to subvert the legal process, because the legal case in question wasn't pending against you at the time.
Court of Appeals Judge Taubman showed incredible restraint in writing an opinion that informed the defendant of this rather obvious shortcoming in his appellate theory without the slightest bit of snark.