Under N.J. R. Evid. 56(2), an expert may testify as to matters requiring scientific, technical or other specialized knowledge if such testimony will assist the trier of fact to understand the evidence or determine a fact in issue. In effect, this rule imposes three basic requirements for the admission of expert testimony: (1) the intended testimony must concern a subject matter that is beyond the ken of the average juror; (2) the field testified to must be at a state of the art such that an expert's testimony could be sufficiently reliable; and (3) the witness must have sufficient expertise to offer the intended testimony.
Defendant was charged with murder after stabbing her husband. At trial, defendant attempted to argued that she suffered from battered spouse syndrome and that the stabbing was an act of self-defense. However, trial court excluded defendant's expert's testimony regarding battered spouse syndrome, regarding it as irrelevant. The jury subsequently found defendant guilty of reckless manslaughter. Defendant argued that the trial court erred in excluding her expert's testimony.
Should the court allow expert testimony to prove battered woman syndrome?
The court held that evidence relating to battered spouse syndrome was relevant in determining whether a reasonable fear of danger existed requisite to a self-defense claim.