Manchester, N.H. — The New Hampshire Supreme Court on Thursday overturned Adam Montgomery’s second-degree murder conviction in the 2019 death of his 5-year-old daughter, Harmony Montgomery, ruling that the trial judge improperly joined the murder charge with a separate second-degree assault count from an earlier incident.

In a unanimous decision issued on June 11, 2026, the justices determined that combining the charges risked prejudicing the jury. They found that the evidence supporting the earlier assault—where multiple witnesses corroborated accounts of Harmony sustaining a black eye—was significantly stronger than the direct evidence linking Montgomery to her death. This misjoinder was deemed not harmless as to the homicide charge.

The court upheld Montgomery’s other convictions related to the case, including second-degree assault, falsifying physical evidence, witness tampering, and abuse of a corpse. He also faces upheld sentences from prior firearms offenses. Montgomery remains incarcerated, serving a minimum 43.5-year sentence on the affirmed convictions.

Harmony Montgomery was reported missing in 2021, though authorities believe she was killed in late 2019 while living with her father in Manchester. Her body has never been recovered. The case gained national attention due to revelations of systemic failures in child protective services in both Massachusetts and New Hampshire, including inadequate oversight and poor coordination between states.

Montgomery was convicted in 2024 of second-degree murder and sentenced to 56 years to life. Prosecutors have announced they will retry the murder charge. New Hampshire Attorney General John Formella expressed disappointment with the ruling but affirmed the office’s commitment to pursuing justice.

Harmony’s mother, Crystal Sorey, described the decision as “shocking and heartbreaking,” noting it came just days after what would have been Harmony’s 12th birthday.

Former Manchester Police Chief Allen Aldenberg, who oversaw the initial investigation, voiced confidence that prosecutors would secure a conviction in a retrial. Current Manchester Police Chief Peter Marr expressed disappointment but emphasized faith in the Attorney General’s Office and the ongoing importance of seeking justice for Harmony.

The ruling highlights ongoing debates about trial procedures, evidentiary standards, and the balance between ensuring fair trials and delivering justice for victims. Defense attorney Pamela Phelan, who argued the appeal, welcomed the decision as upholding principles of a fair trial.

Harmony’s disappearance and death continue to resonate in the community, serving as a stark reminder of vulnerabilities in child welfare systems. Prosecutors are expected to move forward with preparations for a new trial on the murder charge.