The New Jersey rules of evidence state that an expert’s opinion must be based on “facts or data,” or it will be deemed inadmissible as a “net opinion.” The net opinion rule prohibits speculative testimony.

In Faccas v. Young, the plaintiff sued for injuries she sustained in a car accident. The plaintiff’s expert prepared a report concluding that a Jersey Central Power & Light utility pole’s location obstructed the defendant driver’s view, and that the accident may not have occurred if the pole had been moved back twelve inches. However, the expert failed to make a causal connection between the location of the pole and the accident, and he failed to demonstrate how moving the pole twelve inches backwards would eliminate the obstruction. The court concluded that the expert opinion was an inadmissible net opinion.

This case is of interest because it demonstrates that experts must give the why and wherefore of their opinion and must support their conclusions by factual data to be admissible.

Thanks to Heather Aquino for her contribution to this post.