The story of Hailey Dunn is something West Texans are all too familiar with.

The young Colorado City cheerleader went missing back in 2010, but there are still many questions that surround the case and no arrests have been made.

Hailey Dunn was a bright kid with a winning smile.

"She was a tomboy but she like glittery stuff and pretty things," said Hailey’s mother, Billie Dunn.

But 6 years ago she became the focus of a murder mystery.

Her mother, Billie Dunn, says the last time she saw Hailey was few days after Christmas.

"I was on my way to work, so just peeking in her bedroom, seeing her in the bed and off to work."

But when she returned home later that night Hailey wasn't around. She says she had a hard time believing that Hailey would run away.

"Anybody could have been driving through this town and saw my daughter playing outside or walking to the store and picked her up."

Police focused on those closest to Hailey. Billie and her live-in boyfriend Shawn Adkins were already on their radar.

911 records show the couple had a tense and combative relationship, but Shawn eventually moved in.

In the days after Hailey’s disappearance friends, neighbors and police combed the fields around town for any sign of the missing 13-year-old. But her mother Billie never joined the search party.

“I wouldn't partake in looking in the fields because for me that meant we're looking for a body. I couldn't bring myself to do that so I did the flyers and the Facebook and the media,” explained Billie.

And what about her live in boyfriend Shawn Adkins? He wasn't involved in foot searches at all.

“He really didn't help me pass flyers and things. I think he just wanted to stay out of the spotlight,” said Billie

Police asked both Billie and Shawn to take polygraph tests. Billie does so willingly.

According to a police affidavit, she was under the influence of narcotics when she sat down for the first test. So days later she sits down again, and the outcome was a shocker.

“I was told by the DPS reviewer that gave it that deception was indicated.”

Neither Dunn nor police will say exactly which questions raised concerns but the results make cops dig deeper.

A search warrant uncovers an alarming stash of disturbing literature in the house. Police found Billie and Shawn had collected many articles about serial killers.

“Anything to make me look bad. I mean I’m not the only true crime fanatic I’m not the only viewer you have,” said Billie

But our partners at Crime Watch wanted to hear what Billie’s ex-husband Clint Dunn had to say about her reading habits.

“They were doing a lot of research, a lot of research for some reason and it's awfully peculiar that they did all this research and then my daughter is missing murdered.”

Clint says he was disgusted by what is happening at Billie’s house in the days following Hailey’s disappearance.

“They threw a new year's party 4 days after she was missing. They had beer and watched the ball drop on New Year’s while I was standing on my back porch watching my house waiting for Hailey to come home. That's how I know they partied. I was watching them carry the beer in.”

When Adkins is hooked up to a lie detector everything changes.

According to affidavits, he failed the first two tests and on the third try investigators say he showed deception.

Billie says even she's got some serious doubts about her on again off again boyfriend Shawn Adkins.

“Maybe he's pretending to be this nice guy and my friend and my comforter but maybe he's actually evil enough to do something.”

And then two years after Hailey’s disappearance a break in the case. A hiker comes across a skull and bones at Lake J.B. Thomas about 20 miles north of Hailey’s home.

The case gets colder by the day but Billie promises that will change.

“I will find your killer. It's my job to take care of that now. Hailey has no worries. Be in heaven and sing with the angels I’m the mom. I'm your voice.”

After six years, Hailey’s remains were finally released to family earlier this year.

She was laid to rest in January in Luling Texas, just outside of Austin.