In People v. Maragh (94 NY2d 569, 729 N.E.2d 701, 708 NYS2d 44 ), the court addressed whether two nurse-jurors' personal professional expertise, communicated to the rest of the jury, constituted juror misconduct such that the guilty verdict should be set aside. At issue was the conflicting medical testimony from the prosecution and defense experts. The two nurses shared their professional expertise with the other jurors to support the prosecution experts and dispute those of the defense.
In reversing the conviction, the Court of Appeals noted the "grave potential for prejudice" when a professional shares his or her expertise to draw "an expert conclusion about a material issue in the case" (94 NY2d at 574, 708 NYS2d at 47).
"Other jurors are likely to defer to the gratuitous injection of expertise and evaluations by fellow professional jurors, over and above their own everyday experiences, judgment and the adduced proofs at trial" (Id.).
Thus, reversible error occurs when "(1) jurors conduct personal specialized assessments not within the common ken of juror expertise and knowledge (2) concerning a material issue in the case, and (3) communicate that expert opinion to the rest of the jury panel with the force of private, untested truth as though it were evidence" (Id.).