NJ Supreme Court Allows Expert Causation Testimony

The New Jersey Supreme Court has clarified the scope of a criminal defendant’s right to present causation-focused evidence in a vehicular homicide prosecution, holding that a man accused of killing a 94-year-old woman in a head-on crash may offer expert testimony disputing whether his alleged recklessness caused her death. In a unanimous decision, the court reversed an appellate ruling that had required a pretrial evidentiary hearing to assess admissibility. The opinion underscores that when causation and the “within-the-risk” element are legitimately contested, jurors—not judges at preliminary hearings—generally decide what weight to give competing medical explanations for a death.

Crash Allegations and Medical Timeline

The prosecution arises from a June 2019 collision in Union Township, New Jersey, in which Thomas J. DiNapoli crossed double yellow lines and struck an oncoming Chevrolet head-on, according to the court’s recitation of the facts. The opinion notes that DiNapoli later provided police with conflicting accounts of what precipitated the crash. Testing also allegedly showed clonazepam in his system at a level above a normal therapeutic dosage, along with a cocaine metabolite, facts prosecutors have relied on in advancing a theory of recklessness and foreseeability.

The victim, Michelina Mele, 94, was transported to a hospital with multiple traumatic injuries, including rib and patella fractures and lung injuries, the court said. She died later the same day after her family requested that she be placed on palliative care. An autopsy listed the cause of death as “blunt impact injuries” and the manner of death as an “accident.” Against that backdrop, the dispute in the case has centered on whether Mele’s death should legally be attributed to the crash itself or whether subsequent medical decisions and treatment were an intervening cause severing or narrowing criminal responsibility.

Defense Causation Theory and the Scope of Expert Testimony

DiNapoli sought to introduce testimony from three defense experts to challenge the state’s theory that his conduct was the legal cause of death. The Supreme Court described the proposed defense proofs as converging on a core contention: despite Mele’s Alzheimer’s disease and dementia, she would have recovered from the crash-related injuries if she had not been placed on palliative care and received certain medications associated with end-of-life treatment. The state argued that the opinions were irrelevant and inadmissible because, in its view, they did not meaningfully rebut but-for causation in a way that matters under the vehicular homicide statute.

The Supreme Court rejected that framing and emphasized that disagreements among defense experts do not automatically bar admission; evaluating internal tensions, methodological differences, and overall credibility is “the jury’s job,” the court explained. The decision also recognized that a defendant may attempt to show an intervening cause where the evidence supports it, particularly when the manner and character of the death are disputed. The defense is represented by Caruso Smith Picini, according to court filings, and the ruling positions the causation dispute as one for trial presentation rather than pretrial exclusion.

The Supreme Court’s Reversal and What It Requires Going Forward

Procedurally, the trial court initially permitted the defense experts, but the state appealed and the Appellate Division ordered a hearing to determine admissibility. The Supreme Court reversed, holding that a pretrial evidentiary hearing was not required on this record to screen the defense opinions. The justices highlighted that vehicular homicide requires proof of both factual causation and an additional causal element under N.J.S.A. 2C:2-3(c), which addresses whether the result was within the risk the defendant was aware could occur. Prosecutors indicated an intent to pursue both but-for causation and the theory that the death was the kind of result DiNapoli knew his conduct could produce, making the defense experts’ focus on the mechanism and progression of death relevant to the contested elements.

The ruling also imposes a practical case-management directive: the state must disclose at the earliest possible stage—no later than the pretrial conference—which theory or theories of causation it intends to pursue, so defendants can prepare responsive arguments and evidence. The Supreme Court remanded the case to the trial court for further proceedings consistent with its opinion, clearing the way for the defense to present competing medical causation testimony to the jury. More broadly, the decision signals that, in close causation disputes, New Jersey courts should be cautious about using pretrial procedures to foreclose a defendant’s ability to contest how and why a death occurred.