A New York music teacher has been accused of killing his sister-in-law, a 25-year-old doctoral student, after prosecutors said he had fixated on her for more than 10 years.
Joseph Horner, 27, is facing a second-degree murder charge in the death of Victoria Castle, a Stony Brook University Ph.D. student who was found unresponsive by Nassau County police inside a North Massapequa home on June 29.
A felony complaint submitted in Nassau District Court claims Horner intentionally caused Castle’s death, though the filing does not outline the specific circumstances behind the allegation.
Joseph Horner was charged with second-degree murder in connection with the death of his sister-in-law, Victoria Castle. (Nassau County Police Department)
The New York Post, citing statements made by Nassau County prosecutors at Horner’s arraignment, reported that authorities alleged Horner had been “obsessed” with Castle for more than a decade.
Prosecutors also claimed Horner drew Castle to the home by asking her to help move a piano while his wife was away on a bachelorette trip, then allegedly put her in a chokehold, sexually assaulted her and strangled her.
According to the Post, prosecutors said Horner called 911 after the alleged attack, stayed at the residence until officers arrived and later told detectives he was responsible for the killing.
Victoria Castle is seen celebrating an academic achievement in a photo posted to social media. (Vic Castle Facebook)
News Agency has requested the arraignment transcript from Nassau County Court to independently review prosecutors’ statements. The Nassau County District Attorney’s Office declined to comment beyond the record made during the June 30 arraignment.
According to Nassau County police, officers responded at approximately 8:44 a.m. Monday to a North Oak Street residence after receiving a 911 call requesting an ambulance for a woman who was not breathing.
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Officers found Castle unconscious inside the home. She was transported to a nearby hospital, where she was pronounced dead.
Horner was arrested at the scene and charged with second-degree murder, police said.
Court records show Horner is scheduled to return to Nassau District Court in Mineola on Thursday morning.
According to information on her Facebook account, Castle was pursuing a Ph.D. at Stony Brook University and worked there as a research assistant.
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Victoria Castle poses for a selfie during a hike in an undated social media photo. (Vic Castle Facebook)
Less than three years before her death, Castle shared a heartfelt message celebrating her sister’s marriage to Horner.
“My sister, my person, my partner in chaos, is now married to one of the most wonderful people in the world,” Castle wrote alongside a wedding photo. “I love you both forever!”
Horner is employed as a music teacher in the Oceanside School District. Following his arrest, the district announced he had been placed on administrative leave.
“We understand that this news is deeply disturbing,” Superintendent Dr. Phyllis Harrington said in a statement.
District officials said Nassau County authorities informed them the allegations “have no connection to the school district or its students.”
“This staff member has been placed on administrative leave effective immediately, pending further review,” the district said. “The Oceanside School District is committed to maintaining a safe, professional, and trustworthy environment for our students, staff, and community. We stand by that commitment at all times.”
Horner’s attorney, Gregory Grizopoulos, acknowledged the seriousness of the allegations but urged the public not to rush to judgment.
“These are very serious and disturbing allegations, and there’s a very stark contrast between the allegations and his beloved reputation that he had as a teacher, with both his students and his fellow teachers,” Grizopoulos told News12 Long Island.
Victoria Castle worked as a research assistant while pursuing a Ph.D. at Stony Brook University, according to her Facebook account. (Instagram/@vooozaa)
“His family is devastated by the loss of their family member, Victoria, as well as the allegations against their son, Joe. We’ll continue to evaluate the evidence as more details are disclosed to us.”
If found guilty of second-degree murder, Horner could be sentenced to 25 years to life in state prison.
Horner’s attorney did not immediately respond to News Agency’s request for comment.



