RIVERHEAD, N.Y. — Kacy Corso is set to serve seven years in prison after admitting guilt in a notable manslaughter case tied to the death of Christopher Millwater, whose life was cut short outside the Stony Brook Yacht Club. The latest developments in this case also include a guilty plea from her co-defendant, Victor Panebianco, who is now awaiting his own sentencing.
Corso, 34, entered her plea for first-degree manslaughter and hindering prosecution during a court appearance on July 22. Originally charged with second-degree murder in connection with the stabbing of the 52-year-old Millwater on November 10, 2025, she is scheduled to be sentenced on September 2. The plea bargain also includes her commitment to assist prosecutors in their ongoing investigations. Meanwhile, Panebianco, who allegedly delivered the fatal blow after arriving at the yacht club with Corso, pleaded guilty to first-degree manslaughter on August 11.
The resolve of their pleas marks a significant shift in a case that began less than a year ago when Millwater was discovered with severe injuries along Shore Road in Stony Brook. Suffolk County police responded to the scene shortly after 3 a.m., and Millwater was transported to a local hospital where he was pronounced dead. Initially labeled a victim of violence, details about the events leading to his death soon emerged as investigators built the case against both Corso and Panebianco.
Surveillance footage revealed a troubling sequence of events that started when Corso drove into the yacht club parking lot with Panebianco as her passenger. Millwater, who had arrived shortly thereafter, attempted to maneuver around Corso’s vehicle, which blocked his exit. Prosecutors stated that Corso collided with Millwater’s car, prompting him to flee on foot. Panebianco allegedly pursued him while brandishing a weapon, leading to the fatal stabbing, with witnesses recalling Millwater’s pleas for help during the confrontation.
While Corso’s testimony at her plea hearing narrowed the scope of her involvement, she still acknowledged an intention to cause serious injury, despite denying any premeditated plan to kill Millwater. Her attorney afterward emphasized that Corso accepted responsibility for her actions, although the prosecution previously painted a more culpable role for her in the events leading to Millwater’s death.
The complex relationships among the individuals involved drew attention as social media posts indicated connections between the three. Millwater was Corso’s former boyfriend, while Panebianco was reportedly her partner at the time of the incident. Though the nature of these relationships remains a focus of media scrutiny, prosecutors have not confirmed a direct motive linked to their online interactions.
Millwater had lived in the area for many years, and tributes from family and friends have surfaced since his death, highlighting his passion for fishing in Stony Brook. His funeral home obituary described his life span as December 8, 1972, to November 10, 2025. Those close to him have sought to understand how a simple waterfront gathering turned into a homicide scene.
The investigation expanded beyond New York state, leading to Corso’s arrest in Suffolk County once she was publicly identified. Panebianco was apprehended in North Carolina before being returned to New York. When both were indicted in December, authorities indicated that they were residents of King, North Carolina, and emphasized their coordinated actions during the incident.
As the prosecution now pivots toward sentencing, the plea agreements and the stark contrast in potential penalties for both defendants are noteworthy. Corso’s anticipated seven-year sentence comes with her cooperation with prosecutors, whereas Panebianco faces significantly steeper consequences, with discussions of a possible 25 years to life behind bars.
The upcoming court dates for both defendants will mark the final stages of a case that has shifted from a potential murder trial to admissions of manslaughter. Corso will be sentenced on September 2, followed by Panebianco on September 22. The plea acknowledgments have moved the case forward, focusing on sentencing rather than a trial, closing one chapter while raising lingering questions about the circumstances surrounding Millwater’s tragic death.