The disappearance of 17-year-old Alissa Turney became a top priority last year for Phoenix police Dets. Will Andersen and Stuart Somershoe, who were tasked with investigating the seven-year-long mystery.
Alissa went missing on the last day of her junior year at Paradise Valley High School in Phoenix in May 2001. Aside from a brief phone call to her stepfather, Mike Turney, she has not been heard from since.
"Years start passing, and I think that's the point where those heavy feelings really start to settle in, and you really start to wonder," Alissa's friend Charity Thompson said.
A confession from a self-proclaimed serial killer in Florida gave detectives their first lead. The man, Thomas Hymer, successfully identified Alissa from a photo lineup in 2006. But as the detectives pored over Hymer's letters and spoke with investigators in Florida, certain elements of his story didn't add up.
If you have information that might help solve the mystery of what happened to Alissa Turney, please contact the Phoenix Police Department on their Web site, or by phone 1-480-WITNESS, 1-480-948-6377.
"He says she's a heroin addict, nobody said that she was a heroin addict," Somershoe told ABC News. "That's not something you can hide from your friends or your family. So, that didn't match up with what Hymer was saying. He also said that she had some unusual sexual traits and, again, talking to her boyfriend, this did not match with Alissa."
Hymer later failed a polygraph examination and investigators now believe he had seen Alissa's photo in a newspaper prior to his confession.
On the surface, Alissa, who would now be 25, seemed like a typical teen. But upon reviewing the case thoroughly, police say, something didn't seem right. According to investigators, she never called or tipped off friends, she left behind her cell phone, her hairbrush and makeup and never touched any of the $1,800 in her bank account, only a few blocks from where she lived.
As the two detectives looked closer, interviewing friends and other family members, strange details about her life at home emerged.
"We learned that there was surveillance equipment inside the house," Somershoe said, "Not just security outside. There was also a camera on the inside and a vent in the living room. So, basically, Mike was watching his own children through a video camera."
Although Turney told detectives he put the cameras up for safety reasons and not to spy on his children, he then sent police clips of his stepdaughter with boys from the months before she disappeared, suggesting that her boyfriend and mysterious men she met at work be investigated as potential suspects.
When the detectives inquired about the surveillance video from the day she went missing, Turney, a former sheriff's deputy, told them he had reviewed all eight hours of that tape back in 2001 and saw nothing. But he never produced the tape for the two detectives.
CLICK HERE to see photos of Alissa through the years.
"Even if you think it shows nothing criminal, it shows me what she's wearing. It shows me how her hair was styled," Andersen said. "It shows her walking out of the home, which would direct my attention somewhere other than that home. His opinion of nothing is different than my opinion of nothing. I want that tape."
The detectives also became aware of a passive recording system on the home telephone. All calls going in and going out were automatically recorded in the Turney household.
"So that's another interesting thing," Andersen said. "If Alissa called that home, early in the morning, unsolicited, I would expect there to be a recording of it."
Turney told investigators that he used the recordings to assist in his complaints and lawsuits against businesses and a local union with which he had a workplace grievance. He told ABC News that the device was not activated the morning that Alissa called.
As for life in the Turney home, many people who were close to the teen say Alissa's relationship with her father was severely strained, that she didn't like to be at home and that she said Turney tried to control everything she did.
Her stepfather said, "She was quite a handful. A little pistol. Some might call it difficult to deal with but ... I took it as a challenge."
Katie Rothweiler, a grade school friend, said, "When Alissa was around her friends, she was a completely different person than when she was around her family. She just radiated when she was out and about with friends, and it seems like that, that energy that she had kind of got sucked back in when she went into her home."
Some friends suggested that Alissa felt demeaned by Turney.
"My experience of Alissa was that she was a very intelligent person and a lot of times that she would confide in me," Thompson said. "[Mike] made her feel as though maybe she wasn't as smart as she believed herself to be. It was almost to the point where it was constantly eating up at her and, you know, just really deeply hurting her inside."
Stepdad speaks out and answers tough questions on "Primetime Crime" Wednesday at 10 p.m. ET
Detectives say that through their extensive interviews, they learned that the only person Alissa seemed to have issues with was her stepfather. One of those issues, according to investigators, may have involved allegations of sexual abuse.
In an interview with police, one friend said that Alissa had told him her stepfather had tried sexually abusing her when she was younger. The friend claimed that Alissa told him it happened after school one day, when her father had picked her up early.
"[He] pulled over into an unoccupied area -- somewhere in the desert area, he started fooling around with her, it got aggressive," a friend told police.
Turney has denied the allegation.
Another friend recalled in her interview with police that Alissa told her she once awoke to her father gagging her with a sock.
Turney has denied the allegation.
Detectives later discovered strange parent-child contracts that Turney wrote and had Alissa sign.
When asked about the contracts, Turney told ABC News, "All of my children I did that way. It was an experiment of mine that I learned in some class I took, because I didn't have any raising when I was a child. I learned in a psychology class that you make a contract with your children. That sounded like a good idea to me."
Dr. Steven Pitt, a forensic psychiatrist in Phoenix who consulted on the case for the Phoenix Police Department and viewed one of the documents, said the contracts displayed Turney's need for total parental control.
"Probably the biggest thing that stood out was that Michael Turney had this absolute need for control and dominance of his stepdaughter," he told ABC News. "[The document] was essentially a behavioral contract on steroids that was making myriad tasks on the part of Michael Turney of an adolescent girl that were, in my opinion, wholly -- many of which were wholly inappropriate."
Investigators say Turney exhibited bizarre signs of paranoia and hostility, alleging corruption and conspiracy in law enforcement and hinting that a local union had kidnapped Alissa.
"Based on the original information that I reviewed, it was clear that Michael Turney was not someone that played well with others," Pitt told ABC News. "This is a man who made statements that made other people feel uncomfortable."
And when detectives went to the Turney home looking for the video surveillance from the day Alissa went missing, they say, they found things they never expected.
Inside the house, the investigators found bondage-related pornographic videos, as well as a disturbing film in which a woman was abducted, bound and killed.
Turney said the videos were no reason to suggest that he's responsible for his stepdaughter's disappearance, which he denies.
He says that he returned home the day she disappeared to discover a note from her and then began to look for her. He got a call from her a week later, he says, which would have been the last known contact.
Even after eight years, friends and family say Alissa's disappearance is still a painful and open chapter in their lives.
Turney denies that he harmed Alissa in any way or had anything to do with her disappearance. Alissa's younger sister, Sarah, and stepbrother, Mike, say their father isn't capable of harming his children. They describe him as a good father, who was dedicated to his family.
The Phoenix Police Department is still actively investigating the case and considers Turney to be an "investigative lead."
"The circumstantial case is strong, and it's growing," Andersen said. "There is no one bright spotlight on Michael Turney ... but I have a tremendous number of stars, little bits of information that are illuminating the landscape."
If you have information that might help solve the mystery of what happened to Alissa Turney, please contact the Phoenix Police Department on their Web site, or by phone 1-480-WITNESS, 1-480-948-6377.