Hudson County Criminal Lawyer Blog
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.
What made this case especially compelling was the disconnect between what the detective said and what the trial court told the jury to take from it. Detective Leyman testified that the CSLI could indicate where a suspect was located at the time of the homicide, precisely the kind of location inference the trial court had ordered him not to make. The judge then issued a series of limiting instructions, some during testimony and some afterward, attempting to walk back the implications of what the jury had just heard. Then, in summation, the prosecutor told the jury that a cell phone must be a “stone’s throw away” from the tower it connects to, a claim that directly contradicted everything the court had instructed. The Supreme Court found that this combination of overreaching testimony, contradictory instructions, and aggressive closing argument created exactly the kind of confusion and potential prejudice that the expert witness requirement is designed to prevent.
The Court also noted that its earlier decision in State v. Burney pointed in the same direction. In Burney, the Court had thrown out an FBI agent’s expert CSLI testimony because it was based on nothing more than a personal “rule of thumb” about tower coverage ranges, unsupported by any data or methodology. The Hannah Court observed that Detective Leyman’s lay testimony suffered from the same deficiency, he offered conclusions about location without any technical foundation to support them. The Court was emphatic on this point: the evidentiary standards that govern expert testimony cannot be sidestepped by the choice of witness.
For practitioners working in Hudson, Essex, Union, Passaic, and counties across the state, the practical implications are immediate. Prosecutors must secure a qualified CSLI expert if they intend to use cell phone location evidence at trial, and that expert’s opinion must be grounded in specific data, not general approximations. Defense attorneys, meanwhile, should scrutinize every CSLI-related motion and subpoena with renewed attention, knowing that any attempt to route location inferences through a lay witness is now clearly foreclosed. And in cases where CSLI has already played a role, Hannah may provide a significant foundation for post-conviction arguments. The decision is a reminder that the rules governing what a jury hears and how it is equipped to understand what it hears are not technicalities. They are the architecture of a fair trial.