A 27-year-old Long Island man has been charged with murder after prosecutors said he attacked and killed his sister-in-law inside the Massapequa home where both families lived in separate apartments.
In a report for NBC New York, reporter Pei-Sze Cheng said Joseph Horner, a music teacher employed by the Oceanside School District, was arrested after police found 25-year-old Victoria Castle unresponsive in a ground-floor apartment attached to the home on North Oak Street.
Prosecutors allege that Horner called 911 himself after the attack, then waited outside on the stoop for officers to arrive. He has pleaded not guilty, and the allegations against him remain subject to the court process.
The case has shaken relatives, neighbors, and members of the Stony Brook University community, where Castle was pursuing a Ph.D. Her death has left two closely connected families dealing with a tragedy that prosecutors say unfolded inside the same property they had shared.
Prosecutors Describe A Sudden Attack Inside The Home
According to Cheng’s report, prosecutors say Castle had gone to Horner’s apartment after he asked her to help move a piano.
They allege that, once she was inside, Horner attacked her from behind without warning and placed her in a chokehold until she went limp.
Prosecutors further allege that Horner sexually assaulted Castle after the choking, changed clothes, and then called 911 to request police and an ambulance for a deceased woman.
Detective Lieutenant Daniel Steller of the Nassau County Police Department described the emergency call during the court proceedings.
“The male caller requested police and an ambulance to this location for a deceased female,” Steller said, according to NBC New York.
The allegations describe an attack prosecutors say happened Monday morning, but many of the details that will ultimately matter in court, including forensic evidence, witness accounts, and the full sequence of events inside the home, have not yet been publicly tested.
Still, the initial allegations are severe. They are also deeply personal because the victim and suspect were relatives by marriage and lived only a short distance apart within the same house.
Police Say Horner Waited Outside For Officers
Cheng reported that police said Horner was not difficult to locate because he called 911 himself and remained outside the residence as officers responded.
Prosecutors said he was sitting on the stoop when police arrived at the North Oak Street home.
That detail has become one of the most striking parts of the early case, not because it explains the alleged crime, but because it shows how quickly the matter moved from a private family setting into a murder investigation.
The report did not indicate that Horner tried to flee or conceal his location after the call. Instead, investigators say he remained at the scene and spoke with police.
Authorities later arrested him and charged him in connection with Castle’s death.
Cheng reported that Horner did not speak to reporters as he left Mineola police headquarters after his arrest.
A person remaining at the scene does not resolve questions of guilt or intent. Those questions will depend on the evidence presented in court, not the immediate public reaction to the arrest.
But the fact that Horner allegedly called police himself will likely become an important part of the prosecution’s timeline as the case develops.
DA Says He Told Police He Had Been Interested In Her Since 2017
According to prosecutors, Horner told police he had been interested in Castle since 2017 and acted while his wife was away on a trip.
NBC New York reported that prosecutors characterized those statements as an explanation for why the alleged attack occurred Monday morning.
The accusation is particularly disturbing because Horner and Castle were connected through family, and because they had lived under the same roof in separate apartments.
Horner’s defense attorney, Gregory Grizopoulos, told Cheng that his client had been married for about three years and had lived in the same house as his sister-in-law, who occupied another apartment.
“My understanding is he was happily married for the past three years,” Grizopoulos said. “What the motivation was and what the allegations are, we’ll figure it out as we move forward in court.”
That response reflects the early posture of the defense: the case is still at its beginning, and the motive prosecutors described has not yet been fully litigated.
The allegations also underline how little the public may know about a family’s private tensions, even when people live near one another. Neighbors often see only routines, cars in driveways, and occasional interactions, while serious conflict can remain hidden until something irreversible happens.
A Promising Student’s Death Leaves Family And Community Grieving
Castle was a Ph.D. student at Stony Brook University, according to police and the NBC New York report.
Cheng described her as a young scholar with a promising future whose death has left her relatives devastated.
Stony Brook University said it was deeply saddened by Castle’s death and extended condolences to her family, friends, classmates, faculty mentors, and others who knew her.
The university said it would support members of its community as they grieved.
That institutional response cannot lessen the loss for Castle’s family, but it reflects how widely the effects of a killing can spread. A violent death reaches far beyond the address where it happens, touching classmates, coworkers, professors, neighbors, relatives, and anyone who expected the victim to continue building a life.
A neighbor, Marguerite Defillipis, told Cheng she did not know the couple or Castle well, but she was frightened by what happened so close to her home.
“It’s scary, it’s very upsetting,” Defillipis said. “We were frightened all day yesterday and last night because we live so close to the home.”
Her reaction was measured but familiar in cases like this. Residents may not know the people involved personally, yet the realization that a fatal attack allegedly occurred nearby can make ordinary streets feel suddenly unfamiliar.
Teacher Placed On Administrative Leave As Case Moves Forward
Horner worked as a music teacher for the Oceanside School District, and Cheng reported that the district placed him on immediate administrative leave following his arrest.
The district said it had no further information to release at the time.
Horner pleaded not guilty to the charges filed against him and signed an order of protection requiring him to stay away from his wife, according to the NBC New York report.
He was not granted bail and was scheduled to return to court on July 2, while police indicated that charges could be upgraded as the investigation continued.
The decision to deny bail reflects the seriousness of the charges, but it is not a finding of guilt. Horner is entitled to contest the allegations, challenge the prosecution’s evidence, and receive a full legal defense.
The defense attorney told Cheng that Horner’s relatives were also struggling with the accusations.
“They’re torn,” Grizopoulos said. “Obviously, they love their son. They love their daughter-in-law and their daughter-in-law’s sister.”
That captures the painful complexity of the case. The families are connected through marriage, which means grief, shock, and legal consequences are unfolding across people who may care deeply about more than one person involved.
The Case Will Depend On Evidence, Not Initial Allegations
For now, the public account of what happened comes largely from prosecutors, police, and the initial court appearance.
They allege that Horner lured Castle into the apartment under the pretense of moving a piano, attacked her, sexually assaulted her, and called police afterward.
The defense has not yet presented a detailed alternative account, and the full investigative record has not been made public.
As the case moves forward, prosecutors will need to prove each element of the charges beyond a reasonable doubt. That will likely involve evidence from the home, the 911 call, medical findings, statements to police, and any digital or physical material collected during the investigation.
The early allegations have already left the Massapequa community shaken because of their brutality and because the victim and suspect were family.
But the legal process will determine what happened, why it happened, and whether Horner is criminally responsible.
For Castle’s family and the Stony Brook community, the immediate reality is more personal than the court docket. A 25-year-old doctoral student is gone, and the people who knew her are now left to mourn while a deeply painful case unfolds in public.
A former park ranger and wildlife conservationist, Lisa’s passion for survival started with her deep connection to nature. Raised on a small farm in northern Wisconsin, she learned how to grow her own food, raise livestock, and live off the land. Lisa is our dedicated Second Amendment news writer and also focuses on homesteading, natural remedies, and survival strategies. Lisa aims to help others live more sustainably and prepare for the unexpected.
