Prosecutors Allege Long Island Music Teacher Planned Fatal Attack On Sister-in-Law Before Calling 911
A Long Island music teacher has been charged with murder and rape after prosecutors alleged he used a request for help moving a piano to lure his sister-in-law into his apartment before carrying out a fatal attack.
Joseph Horner, 27, was arrested following the death of 25-year-old Victoria Castle, a doctoral student at Stony Brook University. Horner has been charged with second-degree murder and rape. He has pleaded not guilty to the charges and remains presumed innocent unless and until proven guilty in court.
According to the Nassau County District Attorney’s Office, the incident occurred on June 29 at a multi-family residence in North Massapequa.
Authorities said Horner lived in an upstairs apartment with his wife, while Castle occupied a separate apartment on the ground floor. Prosecutors allege Horner’s wife was away attending a bachelorette celebration when the events unfolded.
During Horner’s arraignment, prosecutors alleged that he asked Castle to come upstairs to help move a piano.
According to the prosecution, Castle agreed to assist, believing she was responding to a routine request from a family member. Prosecutors contend that once she entered the apartment, Horner attacked her from behind, placed her in a chokehold until she lost consciousness, and then sexually assaulted her.
Those allegations reflect the prosecution’s account of the incident and have not yet been proven in court.
Castle was transported to a nearby hospital after emergency responders arrived but later died from her injuries.
Police arrested Horner at the scene.
One of the central allegations presented during the arraignment concerns Horner’s alleged long-term interest in Castle.
Prosecutors told the court they believe Horner had developed an obsession with his sister-in-law over several years after first meeting her through his relationship with her sister. Those assertions form part of the prosecution’s theory of the case and remain allegations that will be evaluated during future court proceedings.
According to prosecutors, Horner contacted 911 after the incident and remained at the residence until officers arrived.
The prosecution further alleges that he made incriminating statements to investigators after police responded to the home. Any statements attributed to Horner, and whether they are admissible as evidence, will ultimately be determined through the judicial process.
The case has drawn widespread attention because of the close family relationship between the victim and the defendant.
Castle was pursuing a PhD at Stony Brook University and has been remembered by friends and classmates as an intelligent and compassionate young woman with a promising future. Tributes from those who knew her have continued to appear following news of her death.
Following Horner’s arrest, the Oceanside School District confirmed that he had been placed on administrative leave from his position as a music teacher.
School officials stated that, based on information provided by investigators, the allegations were not connected to the school district or its students. The district also expressed sympathy for Castle’s family.
Legal experts note that allegations presented during an arraignment are intended to establish probable cause for criminal charges rather than determine guilt.
The prosecution must prove each charge beyond a reasonable doubt, while the defense will have the opportunity to challenge witness testimony, forensic evidence, and any statements attributed to the defendant.
Investigators continue reviewing forensic evidence, digital records, and witness interviews as the case moves through the New York court system.
For Castle’s family, the criminal proceedings represent the beginning of a lengthy legal process as they mourn the loss of a daughter, sister, and doctoral student whose life ended under tragic circumstances. The court will ultimately determine whether the evidence supports the charges filed against Horner.
