New Jersey Supreme Court Bars Shaken Baby Syndrome Testimony as Scientifically Unreliable

The New Jersey Supreme Court ruled that expert testimony attributing injuries to shaken baby syndrome (also called abusive head trauma, or SBS/AHT) is scientifically unreliable and inadmissible in two upcoming criminal trials. In a 6–1 decision, the court concluded the biomechanical evidence presented did not meet the threshold for reliable scientific proof that humans can generate the forces needed to produce the injury patterns attributed to the syndrome.

The majority opinion focused on a lack of consensus within the relevant biomechanical community and emphasized that no validated test demonstrates a person can produce the forces the experts attributed to SBS/AHT. That finding led the court to exclude the proffered expert testimony in both prosecutions.

Justice Rachel Wainer Apter issued a strong dissent, arguing the majority gave undue weight to a subset of biomechanical engineers and discounted the broader clinical consensus cited by major medical societies. She noted that multiple medical specialties—pediatrics, child abuse pediatrics, neurology, neuroradiology, neurosurgery, radiology, ophthalmology and emergency medicine—regularly diagnose and treat cases identified as SBS/AHT.

Wainer Apter (dissent): "No case has ever concluded that evidence of SBS/AHT is unreliable," and she warned the ruling departs from how other courts have treated such evidence.

Medical resources such as the Mayo Clinic describe shaken baby syndrome as resulting from forcefully shaking an infant or toddler, which can cause brain cell injury, swelling, bleeding around the brain and retinal hemorrhages, and in severe cases permanent damage or death. Prosecutors and many medical organizations say SBS/AHT is a leading cause of fatal head injuries in children under 2; advocacy groups estimate more than 1,000 U.S. reports annually.

Defense attorneys and some researchers counter that the diagnostic framework for SBS/AHT has flaws that may have contributed to wrongful convictions. They point to overturned convictions or dropped charges in states including California, Ohio, Massachusetts and Michigan as examples prompting further scrutiny of the science used in court.

The state attorney general’s office declined to comment. The public defender’s office praised the ruling as a landmark for requiring "reliable, well-supported scientific evidence" in criminal cases. Cody Mason, a managing attorney with the public defender’s office, said:

Cody Mason: "Where the science is uncertain, the stakes are simply too high to permit unsupported expert opinions to decide a person’s guilt or to justify separating children from their parents."

The decision is likely to influence how New Jersey courts evaluate complex scientific testimony and may prompt further review of forensic standards and expert practices in child-abuse prosecutions. It also raises questions about the role of multidisciplinary medical consensus versus specialized biomechanical analysis in courtroom settings.