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."