New York Music Teacher Joseph Horner, 27, Charged With Murder of Sister-in-Law Victoria Castle After Alleged Decade-Long Obsession

Joseph Horner, a 27-year-old music teacher in Nassau County, New York, has been charged with second-degree murder in the death of Victoria Castle, 25, a Stony Brook University Ph.D. student and his sister-in-law, Nassau County police announced. Prosecutors allege Horner harbored an obsession with Castle for more than a decade before allegedly luring, sexually assaulting, and strangling her on June 29 at a North Massapequa residence.

The Alleged Attack and Arrest

Officers responded to a North Oak Street home at approximately 8:44 a.m. on June 29 after a 911 call reported a woman not breathing. Castle was found unconscious, transported to a nearby hospital, and pronounced dead. Horner was arrested at the scene.

According to statements made by Nassau County prosecutors during Horner's June 30 arraignment — as reported by the New York Post — Horner allegedly lured Castle to the home by asking her to help move a piano while his wife, Castle's sister, was away on a bachelorette trip. Prosecutors allege he then placed Castle in a chokehold, sexually assaulted her, and strangled her. Horner called 911 following the attack, remained at the residence until police arrived, and admitted to detectives that he committed the killing, prosecutors said.

The Nassau County District Attorney's Office declined to comment beyond the record made at arraignment. Fox News Digital requested the arraignment transcript from Nassau County Court to independently verify prosecutors' statements.

School District Places Horner on Leave

Horner was employed as a music teacher in the Oceanside School District at the time of his arrest. Following the charges, the district placed him on administrative leave. Superintendent Dr. Phyllis Harrington said the news was "deeply disturbing," and district officials noted Nassau County authorities confirmed the allegations have no connection to the school or its students.

Defense Urges Restraint; Sentencing Exposure of 25 Years to Life

Horner's attorney, Gregory Grizopoulos, told News12 Long Island that the allegations stand in "stark contrast" to his client's reputation among students and colleagues, and asked the public to withhold judgment while defense counsel evaluates the evidence. Grizopoulos noted Horner's family is grieving both Castle's death and the charges against him.

Castle had been pursuing her doctorate and working as a research assistant at Stony Brook University. Less than three years before her death, she publicly celebrated her sister's marriage to Horner. Horner is scheduled to return to Nassau District Court in Mineola on Thursday. If convicted of second-degree murder, he faces a sentence of 25 years to life in state prison.