A tragic house fire takes the life of a young single mother. But do the experts have it all wrong?

Sheila Deviney was a small town Oklahoma girl in a fairy tale romance, a cheerleader married to her childhood sweetheart, local football star Tyson Hendrix.

Her parents Susan and Dave Deviney remember watching each chapter of Tyson and Sheila's love story grow.

"'Do you remember what I promised when we were children?' And the next thing we knew she was wearing Tyson's class ring," said Sheila's mother Susan Deviney.

That dream was shattered by divorce years later. Sheila remarried, but that ended in divorce too. Now she was living across the way from her parents in a small home with two young kids, slowly putting her life back together.

"Susan was a good mother to them," said Sheila's father David Deviney.

"She was going to college, she had just got her degree from Murray State," Susan tells Crime Watch Daily.

But on the freezing morning of January 6, 2004, Sheila's mom, a junior high school teacher, is at work and her husband Dave is on the road when they get alarming news from a family friend.

"She called the school and told them that my daughter's house was on fire and that nobody could find her, and so I immediately left. I called school because I was worried that the children were there with her and the school told me that they were there and they were fine," said Susan.

"Nobody could find Sheila," said Dave. "So we were all on the phone calling her. No one could get a response out of her."

The family rushes to her place, only to find it engulfed in smoke, with firefighters on the scene.

"I met the Maysville policeman and I said 'Have they found Sheila?' And with tears in his eyes he looked at me and said 'I don't have that information,'" said Susan.

The house is still smoldering, but that doesn't keep Dave Deviney from finding a way inside. He is determined to find his daughter.

"I couldn't see the floor, there was too much smoke and debris, and I was just sliding my feet through it because I figured I would touch her," Dave tells Crime Watch Daily. "The refrigerator was on fire and I knew it's got Freon in it, and I was afraid there could be an explosion."

His son runs in after him and pulls him out. Thankfully Sheila's children were all in school when the fire started. But as the smoke clears, firefighters make a terrible discovery on the kitchen floor. It's the body of Sheila Deviney, burned beyond recognition.

Susan wonders if a propane heater might have somehow triggered the inferno that killed their daughter.

"She had one propane heater in her living room and they had all slept in there because she had the rest of the house closed off because she couldn't afford all the utilities," said Susan Deviney.

In the aftermath of the fatal blaze, Dave Deviney meets Oklahoma Assistant State Fire Marshal JoAnne Sellars at the scene.

"She walked me through the house and was explaining to me how she thought the fire had started on the north end and blew through the south. Her kitchen stove range there had a pan that had been melted on it," said Dave.

According to the fire marshal's report, the "fire originated on the kitchen stove" and the front left burner was left on with the pot on top of it, concluding "This appears to be an accidental fire."

But there is something about this tragedy that keeps eating at the family. For one thing they say there is the mysterious last phone call that Sheila ever made to a friend shortly before the fire started.

"She said 'Oh, I've got to go, my special friend is here,'" Susan tells Crime Watch Daily.

A special friend?

"I know it was probably a male, but other than that I don't know," said Susan.

And then a revelation that stuns family members to their core: Dave happens to be at the scene when an inspector from the propane company stops by to make his report on the fire.

"I told him, I said, 'Well, the fire marshal wrote it up as an accidental house fire, I just wondered if you felt that way.' He just stopped, turned around and looked at me and he says 'Come with me,'" Dave tells Crime Watch Daily.

And what Dave hears changes everything he has been officially told about the horrifying death of his daughter.

"He opened the front door, and that propane here, he said that heater will not burn like that," said Dave Deviney. "He said there was an accelerant throwed on that. Then he walked in the kitchen where Sheila's body and the range were, he said this was set afire, and then he walked me back to the bathroom, which had no heat source in it, and it's gutted, and he said there was a fire started right here. He said this is not an accidental. This was intentionally set."

"This is her Bible that was beside her night stand, and that was right in the middle of the fire and it still survived," Susan Deviney shows Crime Watch Daily. "All of her handwriting and everything that she had. Her prayers."

The fire was ruled an accident by the fire marshal. But Sheila's inconsolable parents Susan and Dave cannot believe it.

"They kept telling us it was an accident. Over and over until I was crying," said Susan. "After six months I was crying every day and Dave couldn't stand living with me. He was tired of listening to me cry.

And then a major break, as the case makes a head-spinning 180-degree turn: Reports from the medical examiner and the coroner are in, and they say the fire is far from accidental. They say it's a homicide.

The Devineys learned there was an accelerant used.

"It was found all over her body," said Dave.

The coroner's report shows a presence of highly flammable benzene, a major ingredient in gasoline. And toluene, a solvent found in paint thinner. It's also an essential component of TNT. And it's found on Sheila Deviney, in her blood and in her lungs. Those disturbing discoveries lead her parents to a terrifying conclusion: It appears Sheila Deviney was burned alive.

But what about the fire marshal's original findings, that the fire was likely an accident triggered by a pot left on a lit stove burner? A full nine months later, following the autopsy, a stunning reversal on that opinion as well: The new report from the same fire marshal makes it crystal clear, saying: "This was a deliberately set fire," and that the "manner of death was Homicide."

"It's bad enough to just be murdered. But then someone to actually set your whole body on fire, that is cruel," said Susan.

Adding to the family's torment, there are no suspects in the case. And they still wonder, who is the "special friend" that Sheila said was at her door during her last phone call with her friend Dobby. Does Dobby have any idea who this special friend was?

"If she does, she's never disclosed that information to us," said Susan.

The Garvin County Sheriff's Department has no comment, and the Oklahoma State Bureau of Investigation has not gotten back to us. But Susan and Dave have a lot to say about one man who they say was no special friend of Sheila's at all: Tyson Hendrix, her ex-husband and father of her two children.

Early on, did the Devineys think Tyson could have something to do with this?

"Most definitely," said Susan.

Despite her parents' suspicions, Tyson Hendrix has never been named as a suspect in Sheila's death. Still, they say Sheila lived in constant fear of Tyson. In fact, they claim less than a week before the fatal fire, Sheila told her mom something that now haunts her.

"She told me in the hot tub when Tyson had the kids that weekend, she said 'Mom, you don't know Tyson like I do.' She said, 'He's going to kill me,'" said Susan Deviney.

And there's a history here: six years before her death, Sheila did obtain a permanent restraining order against Hendrix after filing a complaint that he was abusing her and the children.

"She was very afraid," said Susan. "In the divorce decree it was stated that when she and Tyson exchanged the children for visitation that they always met in a public facility with people around."

There is no indication that he ever violated the order, but a work report from the fire marshal's office also details interviews with witnesses, including a woman friend who said that days before the fire Sheila told her she expected Tyson to go to jail for back child support.

And Sheila's brother Davey claims Tyson told him he was broke and did not have any money because of what Sheila was doing to him.

And then there's the actual day of the fire, when Sheila's sister-in-law Betty Deviney says she called Tyson's job to tell him Sheila's house was in flames.

"I called his work and the receptionist lady told me that he had left with his brother that morning and that he was not there," said Betty. "And I said 'OK, if he comes back have him call us, it's very important.'"

She says Tyson didn't call her back until later that day.

"When he called back he was very livid," said Betty. "He was so mad and he started yelling at me. 'Why are you calling me? 'Don't call me at my place of employment.' I just handed the phone to my mother-in-law and I said 'Here, I can't deal with him.'"

According to the fire marshal's report, Tyson Hendrix claimed that he was at work when he received a call from Susan Deviney telling him about the fire.

Armed with the new findings of homicide, Susan and Dave Deviney move ahead on their own. They gather hundreds of signatures to convene a grand jury, and Tyson Hendrix is among those called to testify.

Most of the grand jury report is sealed. But Crime Watch Daily has obtained some of the results showing that the grand jury received evidence concerning "several persons of interest," examined "some 30 witnesses" and returned no indictments.

"No indictment, but a further investigation should be done," said Susan.

Susan and Dave say they have spent over $100,000 of their savings in the campaign to get justice for Sheila. And now they are reduced to seeking the only help they can afford.

"We started watching crime shows and see how they solved them, and we realized if it was going to be solved we had to do it ourselves because nobody was going to help us," said Susan.

But help is on the way.

The man the Deviney family has now turned to for justice is Dave Ballard, a soldier returned home from the fire of war in Afghanistan. He found another fire waiting for him in small town Maysville, Oklahoma, this time as a private investigator helping Sheila Deviney's parents in the hunt for her killer.

"You could tell right out of the gate that there was some issues," Ballard tells Crime Watch Daily.

Sheila Deviney was burned to death inside her home. At first it was thought to be a tragic accident, but now experts are calling it homicide by arson. And several factors seem to support that. The fire started mid-morning in the kitchen. Remember, Sheila had to get her kids off to school, and was always awake at that time. How could a fire at 10 a.m. catch her off guard and burn the whole house down?

"I just started poring through their evidence, but it's taken a long time 'cause they had 14 big tubs and trunks of evidence," said Ballard.

Ballard says he's baffled, claiming many of the known facts have not been used to build a case. One big example: the accelerants found on the scene and in Sheila's lungs.

"If you would put that in a rag and put it on someone's face, it would render them incapable of moving, and they found traces of that in her nose, in her nasal cavity," said Ballard. "She was rendered unconscious, but still alive when the fire at her house began."

The Garvin County Sheriff's Department will not say if Sheila's murder is an active investigation -- in fact the department has declined to comment at all.

But Dave Ballard has found that in the year following Sheila Deviney's death, the county sheriff's department did in fact interview witnesses and other people.

"I was able to get a report that outlined actual statements taken from people connected to it that the Devineys were never aware of," said Ballard.

Sheila's parents suspect her first ex-husband Tyson Hendrix had something to do with the fatal fire, but he has never been named a suspect in her death. A grand jury that reviewed the evidence did not indict him.

His name does come up in an exclusive audio-only interview obtained by David Ballard. We are not identifying the witness and have altered his voice.

Deputy: "We haven't proven that Tyson has done anything wrong."

Witness: "I'm just saying I heard the rumor that he was seen leaving there but other than that that's all I know. It's just that she's supposed to have been dead before the fire started and that he was supposed to be seen leaving the scene after. I don't really pay no attention to the rumors."

Deputy: "Would you say that there's more than just a rumor going around since you're being visited by two investigators?"

Witness: "Yeah, I'd say that."

Tyson Hendrix first told the fire marshal in his interview that he was at work the day of the fire. Ballard questions that.

"The receptionist in the office where he worked and his supervisor and the owner of the company all say that he left before 8 o'clock that morning and returned just around 10:30," said Dave Ballard.

That's shortly after the first call came in reporting Sheila's house was on fire.

Ballard also directed us to another witness, who we reached by phone. Her story may be the most shocking of all. And she claims it came straight from Tyson himself on the day of Sheila's funeral. We are not identifying the person.

She said she had a very odd reaction with Tyson at the grave site.

"He said how hard it had been on him because he was the first person at the scene. He had been working for the electric company and he had been called out to an address where there was a fire. He had been called to turn the electric power off and when he got there he realized where it was."

Remember, that's a totally different story than the one his sister-in-law told us.

"I have so many inconsistencies in Tyson's story for where he was that day," said Ballard.

And don't forget that mysterious "special friend" that Sheila talked about during her last phone call.

"No one knows who it is," said Ballard.

A boyfriend perhaps? Or could it have been her second ex-husband?

Had you ever known her to date anyone else or be in touch with anyone else or see any other cars here?

"I think it was someone other than him because she had asked him to leave the day before," Susan Deviney tells Crime Watch Daily.

The special friend is a mystery and Ballard says so is the person who has been giving his vehicles some special treatment since he's taken on the investigation.

"My rear window of my car was smashed out and all four tires were flattened. They didn't steal anything, they just smashed out the windows," Dave Ballard tells Crime Watch Daily.

Tyson Hendrix may be no more of a suspect in Sheila's murder than the next guy. But Dave Ballard would sure like to pick his brain.

We figured the only thing to do is find Tyson Hendrix and ask him some questions ourselves. And we did.

"I've went through what I've gone through with my family and the kids and the grand jury, and I don't have anything else to add," Tyson Hendrix said.

What happened in the grand jury?

"It's all public record," Tyson said.

Did he have anything to do with the death of Sheila Deviney?

"Ma'am, no I didn't," said Tyson. "There are families that are suffering because this has been drawn on and drawn on. You guys have a good evening.

"All I can go off is what the police department, fire department, sheriff's department has said. That's what I know and that's it," said Tyson.

Were there problems in the relationship?

"No, we'd been divorced for a number of years. She'd been married and divorced and had a live-in," said Tyson. "Y'all have a good evening."

Tyson Hendrix left without another word.

Dave Ballard says he is moving full speed ahead on the case.

"We've got timelines in place and the team is going to start going to people," said Ballard. "We're coming. I work with a team of investigators who are not shaken very easily."

And so back to square one, where any official investigation of Sheila's murder has pretty much been sitting for more than a decade.

Her heartbroken parents Susan and Dave, along with the rest of her family, have moved on in small ways, planting a tree where her home once stood before the murderous blaze that took her life. And that's where they turn when there is simply no place else to go.