New Jersey Criminal Law

New Jersey Supreme Court Holds That Diminished Capacity Requires Expert Testimony

Published on: August 25, 2026 | by Stephen J. Natoli

Courts-Ruling-on-Diminished-Capacity-300x300 The New Jersey Supreme Court has answered a question that has lingered in our criminal courts for decades: can a defendant obtain a diminished capacity jury instruction on lay testimony alone? In State v. Mustafa, a unanimous decision issued on August 3, 2026, the Court held that expert testimony is required both for a defendant to invoke the diminished capacity defense and for a trial court to instruct the jury on it. The Court affirmed the Appellate Division and confirmed that an expert is necessary to support an insanity defense. For anyone who handles serious violent crime cases, this opinion changes how mental health evidence must be developed, and it changes it well before trial begins.

The case arose from a late night shooting on a Monmouth County highway in May 2018. The defendant was driving with his then girlfriend when the victim, traveling on the same roadway, turned on her high beams because one of her headlights was out. The defendant became upset, pulled over to let her pass, then accelerated until he nearly struck her bumper while flashing his own high beams. As her car began to exit, he put his vehicle in neutral, rolled down his window, drew a handgun, and fired. She died of a gunshot wound to the head. A grand jury returned a six count indictment charging first degree murder, weapons offenses, and endangering. Defense counsel initially served notice of an insanity defense, but the defendant later instructed his attorney to withdraw it, and a pretrial memorandum recorded that decision in plain terms, noting that the insanity defense was withdrawn and that there would be no psychiatric expert testimony. The trial court found the waiver knowing and voluntary.

Diminished capacity, however, was raised explicitly at trial, and a fair amount of lay evidence about the defendant’s mental health reached the jury. His then girlfriend testified that he had begun seeing her psychiatrist to obtain Adderall because he liked how it made him feel, that he smoked marijuana daily, and that he had immersed himself in conspiracy research. She described his belief that he was the target of gang stalking, that people were shooting laser beams, radiation, and concentrated microwaves at him, and that he wore tin foil under a baseball cap and helmet to deflect the rays. She said his statements reminded her of a relative who has schizophrenia. On the night of the shooting, she testified, he took Adderall three times within several hours, yelled about people trying to hit him with radiation and follow him, and screamed that he could not take it anymore and had to fight back. The defendant did not testify and called no witnesses. When counsel requested a diminished capacity charge at the close of evidence, arguing that a medical diagnosis was not required, the trial court denied it because there was no medical or expert testimony in the record. The jury convicted on all counts and the defendant received an aggregate life sentence.

New Jersey Supreme Court Rules That Cell Site Location Evidence Requires an Expert Witness

Published on: April 24, 2026 | by Stephen J. Natoli

Cell-Phone-Tower-Expert-300x300 On April 16, 2026, the New Jersey Supreme Court issued a unanimous decision in State v. Jule Hannah that carries significant consequences for how cell phone location evidence can be presented in criminal trials. The Court held that cell site location information, commonly known as CSLI, involves technical and specialized knowledge that is beyond the understanding of the average juror, and therefore must be introduced through a qualified expert witness. The decision affirms the Appellate Division’s reversal of Hannah’s first-degree murder conviction and orders a new trial, drawing a clear line that prosecutors and defense attorneys across New Jersey must now respect.

The case arose from the January 2017 death of Miguel Lopez, who was found shot to death in his car in Bridgeton after crashing into a tree. Investigators developed Hannah as a suspect based on surveillance footage, DNA from a cigar butt recovered from the passenger seat, and cell phone records. At trial, the State sought to use those records to place Hannah in Lopez’s car during the ride from Monroe Township to Bridgeton. Rather than calling a qualified expert, the State presented Detective Sergeant Leyman as a lay witness to testify about which cell towers Hannah’s phone connected to during the relevant time period. The trial court tried to thread the needle allowing Leyman to testify about tower locations while repeatedly instructing the jury that a cell phone’s connection to a tower does not establish where the phone was at any given moment. That tension, the Supreme Court concluded, was precisely the problem.

The Court’s analysis began with a foundational distinction in the rules of evidence between lay and expert testimony. Under New Jersey law, a lay witness can offer opinions based on common knowledge and observation. When a subject is so technical that the average juror cannot form a valid conclusion without guidance, however, expert testimony is required. CSLI, the Court explained, squarely falls into that category. Whether a phone connects to the nearest tower depends not just on proximity but on a constellation of variables such as tower height, antenna direction, terrain and topography, network load balancing, and the technical characteristics of the phone itself. A jury left to draw inferences from raw call records, without any expert framework to interpret them, risks attributing far more or far less weight to that data than the evidence actually warrants.

New Jersey Appellate Division Suppresses Evidence From Defective Warrant

Published on: March 19, 2026 | by Stephen J. Natoli

Defective-Warrant-300x300 Search warrant cases often turn on major constitutional questions, but sometimes they come down to something much simpler: whether the State got the basics right on the face of the application. In a published decision issued on March 5, 2026, State of New Jersey v. Carlene Harris and Norman A. Thomas 4th, the New Jersey Appellate Division made clear that courts will not rescue a defective warrant by rewriting it after the fact. In this case, the warrant certification listed the key investigative events with dates that made the information stale, and the State later argued those dates were merely typographical errors. The Appellate Division rejected that argument, holding that probable cause must be evaluated from the four corners of the application itself, not from explanations offered later once the defect is exposed.

The case arose out of a drug investigation in Lakewood. According to the certification submitted in support of the search warrants, officers met with a confidential informant during the week of January 29, 2022, and then conducted controlled buys during the weeks of February 19, 2022, and February 26, 2022. Based on those events, police sought warrants in March 2023 to search two apartments, a vehicle, and a person. But the problem was obvious: if the dates in the certification were taken at face value, the key investigative activity had taken place more than a year earlier, making the information stale for probable cause purposes.

The State argued that the year “2022” was simply a typographical error and that the events actually happened in 2023. It also tried to support that position with police reports submitted later and asked for the opportunity to prove the mistake at a hearing. The trial court rejected that approach, suppressed the evidence, and the Appellate Division affirmed. The panel held that the validity of the warrants had to be judged based on what was actually presented to the issuing judge, not on what the State later wished had been included.