Testimony in the form of an opinion or inference otherwise admissible is not objectionable because it embraces an ultimate issue to be decided by the trier of fact.

NOTE

This section is derived from Proposed Mass. R. Evid. 704; Commonwealth v. Woods, 419 Mass. 366, 374–375, 645 N.E.2d 1153, 1158 (1995); and Simon v. Solomon, 385 Mass. 91, 105, 431 N.E.2d 556, 566 (1982). The critical question is not whether the opinion touches on the ultimate issue, but whether it satisfies Sections 403, Grounds for Excluding Relevant Evidence, 701, Opinion Testimony by Lay Witnesses, 702, Testimony by Experts, and any other applicable sections. See Martel v. Massachusetts Bay Transp. Auth., 403 Mass. 1, 3–4, 525 N.E.2d 662, 664 (1988); Commonwealth v. LaCorte, 373 Mass. 700, 705, 369 N.E.2d 1006, 1010 (1977); Commonwealth v. Almeida, 34 Mass. App. Ct. 901, 902–903, 605 N.E.2d 1251, 1252–‌1253 (1993); Commonwealth v. Lopes, 25 Mass. App. Ct. 988, 990, 521 N.E.2d 1038, 1040–‌1041 (1988), citing Commonwealth v. Sendele, 18 Mass. App. Ct. 755, 760, 470 N.E.2d 811, 814 (1984). Accord M.S. Brodin & M. Avery, Massachusetts Evidence § 7.3.2 (8th ed. 2007).

Improper Vouching. Despite the abolition of the common-law doctrine that prohibited expert opinion testimony on the ultimate issue, the admissibility of such testimony in Massachusetts still depends on whether it explains evidence that is beyond the common understanding of the jury. Commonwealth v. Tanner, 45 Mass. App. Ct. 576, 581, 700 N.E.2d 282, 286–287 (1998). See Section 702, Testimony by Experts. Thus, expert witness testimony which simply amounts to an opinion on the credibility of a witness (improper vouching), on whether the defendant was “negligent,” or on the guilt or innocence of the defendant is prohibited. See, e.g., Commonwealth v. Burgess, 450 Mass. 422, 436, 879 N.E.2d 63, 76 (2008) (“the prosecutor [improperly] asked [the Commonwealth’s expert] to comment on the credibility of the Commonwealth’s theory of the case by asking whether its theory was ‘consistent’ with [the expert’s] observations”); Commonwealth v. Jewett, 442 Mass. 356, 368, 813 N.E.2d 452, 462 (2004) (“in the absence of special circumstances, an expert may not be asked whether a rape or sexual assault has occurred”); Commonwealth v. Richardson, 423 Mass. 180, 185–186, 667 N.E.2d 257, 262 (1996), quoting Commonwealth v. Trowbridge, 419 Mass. 750, 759, 647 N.E.2d 413, 420 (1995) (“[a]lthough expert testimony on the general behavioral characteristics of sexually abused children is permissible, an expert may not refer or compare the child to those general characteristics”); Birch v. Strout, 303 Mass. 28, 32, 20 N.E.2d 429, 431 (1939) (defendant could not be asked to “pass upon the question of his own negligence”); Commonwealth v. LaCaprucia, 41 Mass. App. Ct. 496, 498, 671 N.E.2d 984, 986 (1996) (“Dr. Gelinas went beyond the description of general principles of social or behavioral science that might assist the jury in their deliberations concerning credibility and gave testimony concerning family dynamics that evolved into profile testimony that signaled the jury that the child complainants were sexually abused.”).

At least four different, but related, reasons are given for the exclusion of such evidence. First, such opinions offer no assistance to the fact finders “because the jury are capable of making that assessment without an expert’s aid.” Commonwealth v. Colin C., 419 Mass. 54, 60, 643 N.E.2d 19, 22 (1994). See Commonwealth v. Andujar, 57 Mass. App. Ct. 529, 531, 784 N.E.2d 646, 647–648 (2003). Second, “[o]n such questions, the influence of an expert’s opinion may threaten the independence of the jury’s decision.” Simon v. Solomon, 385 Mass. 91, 105, 431 N.E.2d 556, 566 (1982). Third, such questions call for opinions on matters of law or mixed questions of law and fact, and the jury must be allowed to draw their own conclusions from the evidence. See Commonwealth v. Hesketh, 386 Mass. 153, 161–162, 434 N.E.2d 1238, 1244 (1982); Birch v. Strout, 303 Mass. at 32, 20 N.E.2d at 431. Fourth, expert opinion in the form of conclusions about the credibility of a witness or a party are beyond the scope of the witness’s expertise and in the realm of speculation and conjecture. See Commonwealth v. Gardner, 350 Mass. 664, 666, 216 N.E.2d 558, 560 (1966). Cf. Commonwealth v. Colon, 64 Mass. App. Ct. 303, 312, 832 N.E.2d 1154, 1161 (2005) (“while an expert may not opine as to whether a particular child has been raped or sexually abused, an expert may opine, after a physical examination of the victim, that a child’s vaginal injuries are ‘consistent with’ penetration”).

Illustrations. For examples of cases applying this section, see M.S. Brodin & M. Avery, Massachusetts Evidence § 7.3 (8th ed. 2007); 3 M.G. Perlin & D. Cooper, Mottla’s Proof of Cases in Massachusetts § 83.4 (3d ed. 1995).

Legal questions, as to which testimony is not permitted, should be distinguished from factual conclusions, as to which testimony is proper. The line between a “conclusion of law” and an “ultimate factual issue” is sometimes blurred. Commonwealth v. Little, 453 Mass. 766, 769, 906 N.E.2d 286, 290 (2009) (“Narcotics investigators may testify as experts to describe how drug transactions occur on the street . . . [such as] testimony on the use of lookouts in drug transactions, and the significance of the purity of seized drugs. We have also repeatedly held that there is no error in allowing a police detective to testify that in his opinion the amount of drugs possessed by the defendant was not consistent with personal use but was consistent with an intent to distribute.” [Citations and quotations omitted.]). See Commonwealth v. Roderiques, 78 Mass. App. Ct. 515, 522, 940 N.E.2d 1234, 1239–1240 (2010) (pediatrician allowed to testify that baby’s injuries were not accidental). Cf. Commonwealth v. Brady, 370 Mass. 630, 635, 351 N.E.2d 199, 202 (1976) (insurance agent may not testify to applicability of insurance coverage); Perry v. Medeiros, 369 Mass. 836, 842, 343 N.E.2d 859, 863 (1976) (building inspector cannot give opinion interpreting building code); Commonwealth v. Coleman, 366 Mass. 705, 711, 322 N.E.2d 407, 411 (1975) (medical examiner not permitted to testify that death was “homicide”); DeCanio v. School Comm. of Boston, 358 Mass. 116, 125–126, 260 N.E.2d 676, 682–683 (1970) (expert could not testify that “suspension and dismissal of probationary teachers without a hearing ‘would have no legitimate educational purpose’”); Commonwealth v. Gardner, 350 Mass. 664, 666–667, 216 N.E.2d 558, 560 (1966) (doctor in rape prosecution cannot testify to “forcible entry”); S.D. Shaw & Sons v. Joseph Rugo, Inc., 343 Mass. 635, 639, 180 N.E.2d 446, 448 (1962) (witness may not give opinion as to whether certain work was included in contract specification); Commonwealth v. Ross, 339 Mass. 428, 435, 159 N.E.2d 330, 335 (1959) (guilt); Foley v. Hotel Touraine Co., 326 Mass. 742, 745, 96 N.E.2d 698, 699 (1951) (treasurer of corporation could not testify on question whether assistant manager had “ostensible authority” on day of accident); Birch v. Strout, 303 Mass. 28, 32, 20 N.E.2d 429, 431 (1939) (opinion as to negligence).