Sarah Turney Is Still Investigating Her Sister Alissa's Disappearance 23 Years Ago: 'I'll Never Forgive My Father' (Exclusive)

Sarah Turney, 36, has tried everything to find out what happened to her older half-sister, Alissa Turney, who disappeared without a trace at age 17 in 2001. Decades after her devastating loss, Sarah began piecing together painful memories from her childhood in Phoenix and gathered chilling evidence. She now believes her father Michael Turney is solely responsible for Alissa’s death.

“I always thought growing up that Alissa had behavioral problems and that my dad [and Alissa’s stepfather] didn’t like that and was quite controlling,” Sarah tells PEOPLE. She claims her dad used intimidation, surveillance, and psychological and physical abuse to hurt the person who she loved the most. “I’ll never forgive my father. He’s one of the worst people out there.”

Michael, however, has denied killing Alissa and was acquitted of her murder in July 2023. And he denies he ever abused Alissa in a tense conversation with Sarah on Oxygen’s Family Secrets: The Disappearance of Alissa Turney, a docuseries now streaming on Peacock. Despite numerous attempts, PEOPLE was unable to reach Michael Turney.

“Even to this day, there’s never been a single search for Alissa, despite the Phoenix Police Department telling the media exactly where they want to search,” Sarah says. “When I’ve asked, I’m repeatedly told that the area is too vast and it’s too dangerous. At this point, I’ll settle for just one search. Just one.”

Sarah was 4 years old when Alissa’s mother, Barbara Strahm, died of lung cancer. The half sisters grew up in a blended family, after Alissa’s mother remarried a year before she died. Eventually, Alissa’s stepfather Michael adopted her. Michael’s five other children have all said they believe he is responsible for Alissa’s disappearance—and the most vocal among them is Sarah. 

At 12 years old, Sarah was never able to say goodbye when Alissa vanished on the last day of her junior year at Paradise Valley High School in Phoenix, Ariz. When Sarah got home later that day, she found her sister’s bedroom wrecked, with a note on her dresser explaining that she had run away to California.

To Sarah, that seemed plausible. Yet Alissa left her cell phone, money and makeup behind — details that would later strike her half-sister and investigators as peculiar. Their father, Michael, a former sheriff’s deputy and electrician, called in a missing persons report that evening.

“Alissa was saving her money and planning to move out when she turned 18, not to run away. But a handwriting expert did confirm it was her writing,” says Sarah. “I thought Alissa had abandoned me, and I was very, very hurt, so I wasn’t really looking for another motivation. My dad basically convinced me that she was unhappy and that she left.”

Shortly after that, the family moved to another home, and Sarah kept all her sister’s belongings. “I remember being shocked that my father didn’t set up a new bedroom for her in the new house.”

Then, in 2006, the presumed runaway case turned into a possible homicide. A convicted murderer in Florida, Thomas Hymer, seemingly confessed to killing Alissa, according to ABC News. Investigators found his confession to be false, but it resulted in two Phoenix detectives taking a closer look at the teen’s disappearance.

It wasn’t long before they turned their attention to Alissa’s dad. Michael maintained he was innocent throughout the investigation, and continues to do so today. And at first, Sarah believed him.

When he was arrested in August 2020, Sarah and her then-boyfriend were living with him. “When my boyfriend told me that everyone thought that my sister was killed by him, that was obviously really huge for me,” she says. “It became very apparent that I was the only person who didn’t believe this, I was in denial. He was my only living parent and my entire life was shattered.”

“Shouldering all of this alone as the youngest of the family has been really hard,” she continues, holding back tears. “I’ve taken a large step back from all my family after this documentary. They think I’m tarnishing my father’s name. They don’t want this to be our legacy.”

She wishes she had the answers to why her brothers don’t want to continue helping with Alissa’s case. “It’s still hard to grapple with,” she says softly. “But I can tell you that they all believe that [Michael] did this and believed that before I did. I think that’s one of the biggest misconceptions is that I’m over here trying to convince my family when I was the last one to think that this happened. It breaks my heart, and even more so for Alissa. She loved me and her brothers fiercely. I get really defensive for her, and I know that she’d be heartbroken to see how things turned out.”

One night, as Sarah was digging through home videos, she found footage of her sister calling their father a “pervert” in 1997. “I was freaked out. I was terrified when I first saw it,” Sarah says. “I was like, ‘Oh my gosh.’ My first thought is how did the police miss this? And then my second thought was, I need to share this with people.”

Sarah claims she defended her father for so long because she believed him, even when he was behind bars. She says she had to take care of all his assets and all the responsibilities in the home and helped him file over 90 motions in court. “I don’t miss any relationship with him because it was all abuse,” she says now, about her sister.

She claims that Alissa first reported to a school teacher when she was eight years old that she was having sexual intercourse with their father. “That led me to believe this had been happening for a very long time.”

Alissa’s third-grade teacher told authorities that the teen once confided in her that she was having sex with her father, according to NBC News. The teacher did not report the allegation to authorities because she said that Alissa immediately denied it. “But the teacher confronted Mike, and he denied it, saying, ‘Alissa believed sex is when people kiss each other goodnight,'” William Andersen, the Phoenix police detective, told the outlet.

“Our mother had taken us both to a doctor to be checked out for physical and sexual assault before she passed away in 1993,” Sarah says. “She certainly had suspicions if she was taking us to the doctor to be checked for sexual assault. I just wish I knew the results of the testing. But I had been told about the sexual assault by the police when her friends also came forward. Many people have reached out about Alissa telling them about the horrific abuse.”

The first time Sarah confronted her father was around 2014-2015 while he was incarcerated. “I just called him one day, and I was like, ‘Dad, none of this adds up. Why didn’t you tell me all this stuff?’ He essentially blew me off and changed the subject. But once I saw all the evidence, it became pretty clear.” 

Two months after Michael was released from prison, the two spoke again in October 2017 at Starbucks, which is featured in Family Secrets. Sarah interpreted a comment he made—challenging her to come to his deathbed for truthful answers to all the questions she was asking—as a confession. But, as a detective said in the documentary, there was no physical evidence or crime scene, and police couldn’t use “snippets of a conversation” to make their case.

“It was scary,” says Sarah about coming face-to-face with her father. “I did not want to be there. I think it’s always scary talking to my dad, but I just wanted answers and went there looking for an honest conversation. I knew that he wasn’t going to be kind, and I knew that he wasn’t going to tell me the truth, but it was the first time I was able to speak to him in so many years outside of a recorded prison line or without some detention officer watching him, and I was hoping that he would slip up. And he certainly did with many of his statements. It was awful and so shocking.”

She continues: “It erased the 0.01% of doubt I had in my mind that he could have been innocent. It sealed everything for me. I know they don’t talk about it in the documentary, but that’s coupled with him following up shortly after saying, ‘I’ll agree to confess if they give me a lethal injection within 10 days of that confession,’ which she posted on the podcast she created in 2019, “Voices for Justice.”

The last time Sarah spoke to her father was in February of 2024 for the Oxygen documentary. “I don’t think that his words really hurt me anymore. He’s been cruel my entire life,” she says, reflecting on the moment she walked away from her father after she told him to stop gaslighting her about her sister’s death. 

“I just didn’t realize it when I was younger. Now when he’s so outwardly fake like that — it’s irritating and feels like a waste of my time. Let’s just get to the point to what we’re here for and stop pretending we have any semblance of a daughter and father relationship,” she says. “It’s so telling. I think when you listen to that conversation, it’s so clear. He’s so mean, and the statements he says are just so indicative of what he did.”

Today, Sarah cherishes the happy memories of Alissa and has kept all her belongings. She still has her prom dress, writings and drawings, jewelry, furniture, blankets and photos to remember her by. “We used all her actual stuff in the documentary,” she adds. “The blanket at the end of her bed in one scene is from our mom; she knitted it. So yeah, I kept everything.”

But Sarah insists having to relive the pain and talking about what happened to her sister is traumatic for her. “I never wanted to take up this fight. It’s not my first choice, but it’s what I have to do for Alissa, and what police told me to do. I’m willing to hurt and go through this trauma because it helps Alissa— ultimately, it’s not about me,” she says.

“I’ve lost personal relationships over it. I’ve destroyed my employability — and it’s all for her. Unfortunately, there is no true crime entertainment without trauma. It’s extremely difficult and painful, and I have given up truly my entire life for her. I will never give up.”

It’s also her only option to seeking the truth for her sister. “I do believe that my father has [allegedly] been a lifelong serial rapist-murderer, domestic terrorist pedophile. I hope he confesses, but he’s just too selfish. I think he values protecting his ego a lot more than protecting his children.”

She pauses, getting choked up. “I’m going to cry—I always want to say to Alissa that I’m sorry. I wish I was a better sister, that I saw what was happening in our house and that I love her.”