The case of Alissa Turney is explored in Oxygen's Family Secrets: The Disappearance of Alissa Turney. The documentary series premiered on October 13, 2024, and it is re-airing today, July 25, 2025, at 11 AM ET on Oxygen.Alissa Turney disappeared from Phoenix, Arizona, in May 2001, triggering a search for her. Following this, Alissa's sister, Sarah Turney, started her own investigation of the case. She became a prominent voice on social media, piecing together the past and exploring the family dynamics to make sense of Alissa's disappearance.Directed by Ricki Stern and Jesse Sweet, the documentary series follows the story of Sarah Turney, Alissa's sister, who embarked on a difficult journey to uncover the truth behind her sister's disappearance by bringing to light some dark family secrets.Alissa Turney went missing in May 2001The 17-year-old Alissa Turney was reported missing on May 17, 2001, by her stepfather, Michael Turney. Initially, the case was dismissed as a runaway case. Alissa had always wanted to go to California and be on her own because her stepfather was very strict.Years passed, but there was no sign of Alissa, and her family began to suspect that something more sinister was at play behind her sudden disappearance. It was then that the case went from a presumed runaway to a possible homicide in 2006.The last person to see Alissa before she vanished was Michael. Before that, she had stopped by her boyfriend Jon's workshop class to tell him she was leaving school early, as Michael was picking her up. Later, Michael told authorities that he had taken Alissa out for lunch that afternoon, but the two of them got into an argument and he dropped her off at 1 PM.A few hours later, Michael Turney contacted the Phoenix Police to report that Alissa had run away, reportedly leaving behind a note stating that she was heading to California to stay with her aunt.The disappearance case was taken up as a case of homicide for investigationWhile the police opened a missing persons case, they did not interrogate Michael or search the house and her room, even after her aunt said that she never came to California. Michael, on the other hand, told authorities on May 24, 2001, that she had called him from a payphone in Riverside, California, before immediately hanging up. These tips yielded no leads, and the case went cold for two years.During that time, Alissa's younger sister, Sarah Turney, led a campaign to raise awareness about Alissa's case. She suspected that Michael may have had something to do with her disappearance. It was only in 2006, when serial killer Thomas Hymer, who was serving a life sentence in a Florida prison at that time, confessed to murdering Alissa, that the case was taken up again. The police realised that Hymer's confession was false, so they began searching for clues in the case. It was then that attention was turned to Michael Turney as a possible suspect. They interviewed many of Alissa's closest friends, who alleged that her stepfather was abusive.Michael was arrested but not convicted and Alissa's body remains undiscoveredBy December 2008, the police were certain that Michael Turney was responsible for Alissa's disappearance. A search warrant for his house was brought out, which led to an alarming discovery.The police found dozens of homemade bombs, firearms, two silencers, and a 98-page manifesto, which included the details of Michael's plot to commit mass murder at the local headquarters of the electrical workers union. In April 2010, Michael Turney pleaded guilty to possession of unregistered destructive devices. He served a seven-year sentence in federal prison for this.Michael Tiurney was arrested once again on August 20, 2020, on charges of a single count of second-degree felony murder for the death of Alissa. However, Turney maintained his innocence regarding Alissa's disappearance. He was tried and acquitted of Alissa Turney's murder in 2023, as there was insufficient evidence.Alissa Turney's body remains undiscovered, and her family continues to search for answers to what happened to her.