Allowing a Detective Who Was Involved in the Investigation of Defendant’s Case to Testify as an “Expert” Was Error (Harmless Here However)–Although the Detective Was Ostensibly to Testify as an Expert Who Could “Translate” Code Words Used in Recorded Conversations, His Testimony Extended into Many Areas Which Did Not Involve Code Words, Thereby Imbuing HIs Entire Testimony with an Aura of Expertise—Such Improper “Expert” Testimony Usurps the Jury’s Role

Although the error was deemed harmless here, the Court of Appeals, in a full-fledged opinion by Judge Lippman, determined it was error to allow a detective, who was involved in the underlying murder investigation, to testify as an “expert.” The detective was asked to explain the meaning of so-called “code words” used in recorded conversations admitted into evidence. But it was clear that the trial court allowed the detective to testify as an “expert” on matters that had nothing to do with translating code words.  As a result, the detective’s testimony was imbued with an aura of expertise which could have improperly added weight to his testimony in the eyes of the jury.  Because this issue has not been addressed by New York courts, the Court of Appeals turned to two Second Circuit cases which held the improper “expert” testimony, on topics not beyond the “ken of the jurors,” usurped the jury’s role:

We have, for example, permitted expert testimony by a police sergeant respecting the way in which street-level drug sales are transacted to help a jury understand why the failure to recover drugs or marked buy-money from an individual apprehended in a buy-and-bust operation is not necessarily indicative of the accused’s misidentification (People v Brown, 97 NY2d 500 [2002]). It is instructive to note, however, that the testimony of the sergeant in Brown was carefully limited by the trial court to a discrete issue beyond the ken of ordinary jurors, and that the sergeant was not himself involved in the underlying investigation and gave no testimony as to what had actually occurred during the buy-and-bust there involved. The situation is very different where a police officer, qualified as an expert, has participated in the investigation of the matter being tried and, with the mantel of an expert steeped in the particulars of the case, gives seemingly authoritative testimony directly instructive of what facts the jury should find. Our cases have not dealt with this problematic scenario, but those of the Second Circuit, most notably United States v Mejia (545 F3d 179 [2d Cir 2008]) and United States v Dukagjini (326 F3d 45 [2d Cir 2002]), have.

In both of those cases, law enforcement officers involved in the investigations upon which the defendants’ prosecutions were founded were duly qualified as experts but permitted to testify as apparent experts beyond their expertise and upon matters well within the grasp of lay jurors. In exploring the full reach of the permission they had been afforded, they became summation witnesses, instructing the jury comprehensively and with an aura of expertise, as to how the particular factual issues presented in each case should be resolved. This, said the Mejia court, amounted to a “usurpation of the jury’s role” (545 F3d at 191), and was objectionable as well, in both Mejia and Dukagjini, for operating to inject hearsay into the evidentiary mix and to abridge the defendants’ constitutional right to confront the witnesses against them; both case agent witnesses, as putative experts, had premised their testimony largely on inadmissible out-of-court statements, even when that testimony ceased to be expert and went only towards proving particular facts. People v Inoa, 2015 NY Slip Op 04790, CtApp 6-10-15