Joseph Horner, 27, is accused of murdering his sister-in-law on Monday, June 29.
Prosecutors said that Joseph Horner, 27, strangled his sister-in-law, who was found not breathing by police inside a ground-floor apartment on North Oak Street in North Massapequa on Monday morning.
Multiple outlets identified the alleged victim as Horner’s sister-in-law, Victoria Castle.
Joseph Horner, 27, was charged with second-degree murder in connection with the death of a 25-year-old woman at a home in Massapequa, New York, according to the Nassau County Police Department.
Prosecutors say Joseph Horner had lusted over his sister-in-law since 2017.
The district attorney’s office said Horner allegedly had a “twisted fascination” with his sister-in-law, whom he’d met at the same time he met his wife in 2016.
Horner lived in the upstairs apartment of a multi-family home with his wife, while Castle lived in the first-floor unit, the New York Post reported, citing the Nassau County District Attorney’s Office.
Prosecutors said while Horner’s wife was out of town, he asked Castle, who was a PhD student at Stony Brook University, to help him move a piano.
The 27-year-old, who lives in the second floor apartment at the house, asked Castle to help him move a piano when, “without warning and unprovoked,” he attacked her from behind and placed her in a chokehold until her body went limp.
They allege he then placed her in a chokehold until she lost consciousness before sexually assaulting her.
After the attack, prosecutors said Horner called 911 and remained at the scene.
They allege he admitted to detectives that he had choked Castle and had sex with her.
Police said Horner called 911 around 8:45 a.m. Monday, requesting an ambulance for a woman who was not breathing. Upon arrival, authorities performed CPR before the woman was taken to a local hospital, where she was pronounced dead.
At Horner’s arraignment, a Nassau prosecutor said while Horner’s wife was away, he saw an opportunity to follow through on a “sexual desire” he’d harbored for his sister-in-law. Horner allegedly admitted to lusting over his wife’s sister since 2017.
“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.
He added,
“My understanding is he was happily married for the past three years. He lived in the same house with his sister-in-law, who lived in another apartment. What the motivation was and what the allegations are, we will figure it out as we move forward.”
She was a student in the process of getting her PhD at Stony Brook University.
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!”
Cops said Horner confessed to the crime when they first interviewed him Monday, June 29, according to News 12 Long Island.
He told investigators that he’d had “sexual desire” for his wife’s sister since 2017, police said.
Horner pleaded not guilty to the charge at his arraignment Tuesday, with Grizopoulos describing his emotional state as “in shock at the charges and the allegations.” Family of the Oceanside music teacher and victim packed the courtroom, with tears on both sides.
“They’re torn; obviously they love their son, they love their daughter-in-law, and their daughter-in-law’s sister, so they’re in a very emotional state,” Grizopoulos said of Horner’s family. “Their hearts and prayers go out to the family.”
Horner was placed on administrative leave from his former position in the Oceanside School District, the school’s superintendent told News12 Long Island in a statement.
“We understand that this news is deeply disturbing,” Superintendent Dr. Phyllis Harrington said in a statement.
A neighbor who said she didn’t really know the couple or Castle was stunned to learn what happened. “It’s scary, it’s very upsetting. We were frightened all day yesterday and last night cause we live so close to the home,” said neighbor Marguerite Defillipis.
Officials with Stony Brook said in a statement they were “deeply saddened by the loss of Victoria Castle, a valued member of the Stony Brook University community. We extend our heartfelt condolences to her family, friends, classmates, faculty mentors, and all who knew and cared for her.”
In the viral moment that led to charges, prosecutors at Tuesday’s arraignment alleged Horner had harbored sexual desire for Castle since 2017, nearly a decade before her death. While his wife attended a bachelorette party on Monday morning, Horner asked Castle to help him move a piano upstairs to his apartment, according to court proceedings. Once alone with her, he attacked from behind, placing her in a chokehold that rendered her unconscious. After sexually assaulting her body, he changed his clothes and dialed 911, telling the dispatcher a woman was not breathing at the North Massapequa address.
Police arrived within minutes to find Horner waiting on the front stoop. He was arrested at the scene, and Castle was rushed to a hospital where she was pronounced dead. Detectives said Horner immediately admitted to the attack, confessing he had choked Castle and had sex with her. The case shocked neighbors and colleagues who described Horner as a respected, tenured music teacher beloved by students and staff.
Horner was held without bail, and if convicted, he faces 25 years to life in prison.