Long Island music teacher rapes, strangles sister-in-law he lusted over for years while wife out of town: prosecutors

A Long Island music teacher sexually assaulted and strangled his sister-in-law — whom he’d reportedly been lusting over for nearly a decade — while his wife was away on a bachelorette trip, according to police and prosecutors.

Joseph Horner, 27, killed Victoria Castle, his wife’s 25-year-old sister, at their shared North Oak Street home in North Massapequa and then called the cops on himself around 8:45 a.m. on Monday, the Nassau County Police Department said. 

Joseph Horner, 27, strangled his 25-year-old in-law at their shared home in North Massapequa, the Nassau County Police Department and prosecutors said. Nassau County Police Department

Horner – a music teacher in the Oceanside School District – lived in the upstairs apartment of the multi-family house with his wife, and Castle lived in the ground-floor unit, according to the Nassau County District Attorney’s Office.

While Horner’s wife was out of town for a bachelorette party, he took advantage of her absence to act on sick urges he had for her sister – whom he’d lusted after since 2017, prosecutors said at his arraignment.

The warped music teacher asked his in-law, a PhD student at Stony Brook University, to help him move a piano. Then he attacked her from behind — placing her in a chokehold until she went limp, disrobed her and raped her, according to the district attorney’s office.

After the brutal attack, Horner called 911 and waited for the cops to show up, immediately admitting to detectives that he had choked his sister-in-law and had sex with her, prosecutors said. 

After the brutal attack, Horner called 911 and waited for the cops to show up, immediately admitting to detectives that he had choked his sister-in-law and sexually assaulted her, prosecutors said.  New Africa – stock.adobe.com

He was arrested for the homicide at the scene, cops said.

Emergency services rushed Castle to a local hospital, where she died less than hour after the 911 call, according to authorities. 

Horner had a twisted fascination with his sister-in-law, whom he’d met at the same time he met his wife in 2016, the DA’s office said. 

Horner was charged with second-degree murder and is currently being held without bail, according to prosecutors. He pleaded not guilty.

Horner was placed on administrative leave from his music teaching position in the Oceanside School District, the school’s superintendent told News12 Long Island in a statement.

“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,” Horner’s attorney Gregory Grizopoulos said in a statement.

“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,” Grizopoulos added.