Victoria Castle, 25, had pursued scientific research before authorities accused her brother-in-law of killing her at their Long Island home.
STONY BROOK, N.Y. — Before Victoria Castle became the victim at the center of a Long Island murder prosecution, she was a young geoscience researcher learning how grains of sand and buried minerals could reveal the history of landscapes and human communities.
Castle, 25, had studied geology at Stony Brook University and pursued research involving luminescence dating, a scientific method that can help determine when sediments were deposited. A university profile named her its undergraduate researcher of the month in November 2023 and described her enthusiasm for laboratory work, field questions and the stories that natural materials can preserve. Local news reports said she later continued into graduate study and was working toward a doctorate. Her academic record now forms part of the public account of a life interrupted on June 29, when police found her unresponsive at her North Massapequa home.
Nassau County authorities have charged Castle’s brother-in-law, Joseph Horner, 27, with second-degree murder. Prosecutors allege that Horner, an elementary school music teacher, asked Castle to come upstairs to help him move a piano in the apartment where he lived with his wife, Castle’s sister. They say he then attacked Castle from behind, held her in a chokehold until she became unconscious and sexually assaulted her. Horner pleaded not guilty and is being held without bail. The claims against him are allegations, and no court has determined that he is guilty.
The murder case has drawn attention in part because prosecutors describe an act of violence inside a household bound together by close family relationships. Horner and his wife occupied an upstairs apartment in a multifamily house on North Oak Street, while Castle lived in a separate unit, according to accounts of the arraignment. Horner’s wife was out of town for a bachelorette party. Prosecutors contend that her absence created the setting in which Horner brought Castle upstairs by making what appeared to be a routine request for help.
Police said the emergency response began at 8:44 a.m., when officers were sent to the house after a caller requested an ambulance for a woman who was not breathing. Officers found Castle unresponsive and performed CPR. She was taken to a hospital and pronounced dead. Police arrested Horner at the residence. Prosecutors said he had called 911, changed his clothes and waited outside for officers. Authorities have not made the complete call or any full interview recording public, leaving the prosecution’s courtroom account as the main available description of what Horner allegedly told investigators.
Castle’s earlier research profile offers a different starting point for understanding who was lost. She worked with faculty mentor Marine Frouin on luminescence dating and studied sediments from river terraces near Perspektywiczna Cave in southern Poland. The broader project examined environmental change and early human history during the transition between the Pleistocene and Holocene periods. Castle’s part of the work focused on building a chronology for deposits left by the Udorka River, according to Stony Brook’s published account.
That type of research depends on careful sample handling and an understanding of how minerals store energy from natural radiation. When properly collected and tested, samples can help scientists estimate when sediment was last exposed to sunlight before it was buried. In the university profile, Castle described her fascination with the way a small portion of material could yield information about an ancient environment. Her comments conveyed excitement about both the technical process and the larger scientific questions it could answer.
Castle also contributed to research concerning ancient structures in rural Quiechapa in Oaxaca, Mexico. Her senior honors work involved using luminescence methods to help establish a timeline for construction there, the university said. She presented research about the Polish river terraces at a Geological Society of America conference in Pittsburgh. Fellowships and university research grants supported portions of her work, and the profile described her efforts to develop skills in scientific communication as well as laboratory analysis.
The account showed that Castle’s interests extended across geochronology, geomorphology and Quaternary science. Geochronology concerns the timing of events in Earth’s history, while geomorphology examines how landscapes form and change. Quaternary science focuses on the most recent major period of geological time, including dramatic climate shifts and the development of human societies. Castle spoke of wanting to contribute to those fields and said attending a national conference had reinforced her confidence that she had chosen the right path.
Her death halted that work before its full course could be known. The surviving public materials do not state the exact status of her doctoral research in June or identify a dissertation project. They do establish that she had already taken part in substantive research, delivered a national conference presentation and worked with scientists on projects spanning multiple regions. Reporting those accomplishments does not answer the criminal questions now before the courts, but it prevents the allegations against Horner from becoming the only public frame through which Castle is remembered.
Prosecutors said Horner told investigators that he had been interested in Castle since 2017. That alleged statement has been described as a possible part of the prosecution’s account of motive, but authorities have not released evidence showing the nature of those feelings or whether Castle knew about them. No reviewed public report established that she had made a prior complaint against Horner. The distinction matters because prosecutors’ statements at an arraignment summarize their theory of a case; they are not themselves a verdict or a substitute for evidence tested in court.
Horner’s attorney, Gregory Grizopoulos, pointed to his client’s reputation as a tenured Oceanside teacher who was well liked by students and co-workers. The lawyer said the charges were difficult for people close to Horner to reconcile with the person they believed they knew. That defense response focused on Horner’s background rather than disputing each specific allegation described by prosecutors. The defense will have later opportunities to challenge witness accounts, forensic findings, statements and other evidence through motions, hearings or a trial.
The Oceanside School District placed Horner on administrative leave immediately after the arrest. The district said it was conducting a further review and had no additional information to provide. Administrative leave separates an employee from active duties while an employer assesses a serious matter. It does not decide whether the criminal charge is true. Available reports did not indicate that the accusations involved students, school property or conduct within the school system. Under New York law, second-degree murder is a class A-I felony. One provision applies when a person intends to cause another person’s death and causes that death. Local reporting said Horner could face 25 years to life in prison if convicted. Prosecutors will still have to identify their legal theory in formal charging documents and prove every required element. Horner’s not-guilty plea means he has not accepted the accusation and retains the presumption of innocence.
The initial court appearance began a process that can include grand jury review, discovery of evidence, pretrial motions and hearings. A grand jury decides whether prosecutors have shown enough evidence to issue an indictment and continue a felony case. It does not decide guilt. If the case reaches trial, prosecutors would bear the burden of proving the charge beyond a reasonable doubt, while the defense could question witnesses, challenge evidence and offer its own account.
Among the evidence likely to shape the case are medical findings concerning Castle’s cause and manner of death, forensic results from the residence, the circumstances of the 911 call and any statements investigators say Horner made. Authorities had not publicly released those materials in full. It also was not clear from the initial accounts whether additional criminal counts would be presented to a grand jury based on the allegation of sexual assault. Accuracy requires separating that reported conduct from the one publicly confirmed arrest charge of second-degree murder.
Castle’s relatives attended Horner’s early court appearance, where local reporters observed family members crying and embracing. They did not provide public comments about the allegations. The family’s position is uniquely painful because Castle’s sister is also Horner’s wife. That relationship makes the case both a homicide prosecution and a private family loss in which the people mourning Castle are connected to the defendant through marriage.
As the criminal case continues, Horner remains accused but not convicted. Castle’s academic record, by contrast, needs no judicial finding. It shows a researcher who had already learned to draw meaning from difficult evidence, present her findings to other scientists and imagine a future devoted to understanding how the Earth preserves its history. The next legal filings may provide more information about how she died. Her university work provides part of the record of how she lived.
Author note: Last updated July 28, 2026.