The story of a female sheriff's deputy, her bodybuilder boyfriend -- and murder. Many are wondering if an innocent person is currently behind bars.

There are two very different portraits being painted of Tracy Fortson: One, a struggling single mom who became the first female deputy in her county; the other, a calculating killer who encased her victim's body in concrete.

It's a grim and controversial murder case that simply refuses to die.

"This is one of those cases that will never end. There's always those cases," said author M. William Phelps.

But now M. William Phelps, the investigative author of 35 true-crime books, takes us inside the Tracy Fortson case, a woman who's either a heartless killer or a scapegoat in a sensational murder mystery.

"Not only did she say she was innocent, but that she seemed to be making a case for it. And other people seem to be making a case for it," M. William Phelps tells Crime Watch Daily.

Suggesting Fortson may have had a target on her back the day she broke through to become the first female deputy in the history of the Oglethorpe County Sheriff's Office in Athens, Georgia.

"So here was a kind of a Type-A personality female in a man's world," said Phelps.

Fortson's mother was confident Tracy would succeed.

"Tracy was a strong person," said Sharon Hodges, Tracy Fortson's mother. "She told me, you have to be strong, you have to separate yourself from some of the things that you see when you work in law enforcement."

And Tracy Fortson, a 35-year-old single mother of a teenage daughter, relished the challenge.

"She loved what she was doing. She loved being a deputy, even though at times I think that environment was difficult for her to thrive in," said Phelps.

It didn't become any easier when Fortson dared to make a stand for women's rights at the sheriff's office.

"She believed that she wasn't being paid what the men were being paid in her same position, and she thought that was unfair," said Phelps.

Fortson didn't stop there.

"She also started to complain about some of the talk around the office: sexual talk and innuendo and that sort of thing," said Phelps.

And in a phone interview with Crime Watch Daily, Tracy Fortson called out one male deputy in particular:

"Who said something about me being a stripper before I ever came to work at the sheriff's department, which was not true, and he made comments that he had pictures of me with two men, that he never produced," Fortson tells Crime Watch Daily.

She says she tried to brush off the harassment as just another one of the hazards of the job.

"I worked in a man's world. I mean, I was the only female deputy that worked at the sheriff's department, and I grew up around guys, and I know how guys are," said Fortson.

But she says her boyfriend Doug Benton, a 38-year-old welder and bodybuilder, wasn't so forgiving.

"I should never have come home and said, 'Hey, this was said to me, or this was done, or this was insinuated,' or whatever. That was my biggest mistake," said Fortson.

She says an angry Benton persuaded her to wear a wire to sting the sheriff's office.

"We purchased a mini-cassette recorder, and I recorded the sheriff making lewd comments, and some of the other guys in the department," said Fortson.

And with that recording in hand, Fortson says, Doug Benton convinced her to resign and file a sexual harassment lawsuit against the sheriff's office.

"Doug thought I was sitting on a gold mine. He thought there was a lot of money involved. He told me that they would settle out of court," said Fortson.

She says it was difficult to argue with him.

"He was right. I had a good case," said Fortson.

But in hindsight, she thinks it may have been a little too good.

"She says the embarrassment that brought the sheriff's department really caused the set of dominoes to go into motion here," Phelps tells Crime Watch Daily.

The first domino literally dropped like a block of cement: Doug Benton's body was found encased in a metal horse-feeding trough found on Rodney Sturdivant's farm by his property manager Rob Postin.

"And it smelled real bad, so we called the sheriff," Rob Postin tells Crime Watch Daily.

On June 19, 2000, Investigators smashed open the cement block and made a horrifying discovery.

"We pulled the metal back and we saw a person that was wrapped in several different pieces of material," said Georgia Bureau of Investigation Special Agent Ben Williams.

Doug Benton had been shot and stabbed multiple times.

"All over his abdomen area, near his groin area and in his buttocks," said Phelps.

The ferocity of the murder led investigators to believe it was committed by someone close to him.

"The fatal wound was a gunshot to the top of the head," said Northern Judicial Circuit, Georgia District Attorney Robert Lavender.

Investigators begin to search for 38-year-old Doug Benton's killer.

"Doug's friends were polygraphed, doors were knocked on up and down the street, questions were asked, people were brought into the sheriff's department and questioned," said M. William Phelps.

And they all had one thing in common:

"They mentioned Tracy," said Phelps.

Who killed bodybuilder Doug Benton in June 2000?

It's a question investigators are trying to answers, and everyone they talk to seems to be pointing the finger at the same person: Benton's girlfriend, former sheriff's deputy Tracy Fortson.

Doug Benton's body was found inside a block of cement on a farm near Athens, Georgia with a "kill shot" bullet wound in the head, and multiple stab wounds on his lower torso.

And Benton's friends and neighbors tell investigators they think they know who murdered him:

"They all pointed to Tracy Fortson," said District Attorney Robert Lavender.

Fortson, Benton's 35-year-old girlfriend, was the only female deputy sheriff in Oglethorpe County, until she resigned less than four months before Benton's murder.

"It was pretty obvious that she might be a suspect," said Georgia Bureau of Investigation Special Agent Ben Williams.

"There was not any indication that anybody else had done any of this," said Robert Lavender.

Investigators learn that at the time of Doug Benton's murder, Benton and Fortson had been dating for nearly a year after meeting at a gym where the two avid bodybuilders both worked out.

"He was so excited. He said, 'Mom, I met her. I met her. I met somebody that I really like,'" said Carol Benton, Doug's mother. "I was very OK with it. I liked her."

Fortson's mom Sharon was happy for her daughter too.

"Tracy and Doug had a really good relationship. She loved Doug very much," said Sharon Fortson.

But investigators say they heard some disturbing stories about their relationship.

"Everybody they spoke to said there was some type of violence, or really aggressive behavior between the two of them," said true-crime author M. William Phelps, who wrote Targeted: A Deputy, Her Love Affairs, A Brutal Murder about the case.

Phelps says there were reports they'd even threatened to kill each other.

"That Doug and her were pulling guns on each other, sticking guns to their head in arguments," said Phelps.

Tracy Fortson vehemently denied the allegations in a telephone interview with Crime Watch Daily from prison.

"We argued just like any other couple, but we never had a physical fight, never. In the whole course of the time that we dated, we never had a physical fight," Fortson tells Crime Watch Daily.

"Whether it's true or not is beside the point. Law enforcement is getting these stories and they're following them," said Phelps.

And investigators learned Fortson and Benton had one final argument at his house just two weeks before he was found murdered.

"According to Tracy, Doug tells her 'Get out, get out of my house. Go home,'" said Phelps.

Fortson says she obliged.

"He wanted his space," said Phelps. "So Tracy took that as, 'All right, you want your space, I'm outta here,'" said Phelps.

Fortson says she never saw nor heard from Benton again. And nobody else did either after he suddenly vanished.

"That's what we first started investigating, was a missing-persons report," said D.A. Robert Lavender.

The only clue to Benton's whereabouts was a mysterious note found on his car windshield, saying he'd gone out of town and couldn't be reached.

"No one knows where he is, his mother hasn't heard from him, nobody's heard from him," said Phelps.

When Benton was found dead, investigators theorized Fortson had killed him in a violent rage at his house that night they broke up.

"He said 'That's it. She's outta there.' And the guy ends up dead," said Phelps. "Law enforcement began to follow the evidence that was being presented to them, and started going after Tracy."

Investigators found bloodstains in Benton's living room, and alleged Fortson had vainly tried to mop it up.

"She had cleaned the surface of the couch and all that very thoroughly, but of course it soaked through the covering. It was just a massive amount of blood," said Robert Lavender.

Investigators also claim Tracy Fortson tried to later burn down the house to destroy the evidence.

"Someone had gone in and placed scented candles throughout the house, like to start a fire," said Ben Williams. "And I believe there was like the odor of kerosene."

"Of course we pull the carpet up and you could see the stain where the kerosene had been poured through the carpet and up, over and under the couch," said Lavender.

Fortson denies doing any of that, counter-charging that investigators disregarded blood found on a door at the house that belonged to neither her nor Benton.

"DNA at the crime scene was that of a male, and it was significant," Tracy Fortson tells Crime Watch Daily.

Investigators found more evidence in Fortson's home, including ammunition and a .22-caliber rifle they believe was used to fire the bullet found in Benton's head.

"While we couldn't say with scientific certainty that bullet was fired from that rifle, we could say this rifle was among the rifles that could have fired that bullet," said Lavender.

Tracy Fortson claims it was all planted there to set her up.

"I really don't see that a person who is guilty of killing someone would leave the gun in the house, would have bullets in the house that would be fired from that particular gun," said Fortson.

But investigators also found a receipt for a shower curtain they say Fortson bought to replace the one she used to wrap around Doug Benton's body, as well as receipts for cement and a metal feeding trough to encase it that were identical to the materials used to make Benton's concrete coffin.

And investigators found the same cement in the bed of Fortson's truck, which is where they say she put Benton's cement-boxed body to transport it to the farm where it was dumped.

"The salesman remembered her buying the concrete. So there was never any indication that anybody else had done any of this, that had bought the concrete, or bought the trough, or bought the shower curtain," said Lavender.

Fortson doesn't deny buying the cement and the feeding trough, but claims she was going to use the cement to build a dog run, and the trough was for her own animals. She goes on to say those materials were actually stolen, claiming they were probably taken by whoever killed Benton and framed her.

"It just seems like it's a little bit too convenient for everyone involved to point the finger at Tracy and all the evidence stacks up against Tracy," said Fortson.

Georgia investigators had amassed a mountain of damning evidence against Tracy Fortson, the former deputy sheriff they believe shot and stabbed her boyfriend Doug Benton to death before dumping his body in a makeshift coffin.

"I felt like we had a very strong case," said District Attorney Robert Lavender. "It was all circumstantial, but we had over 100 pieces of evidence."

But even investigators themselves can't fathom why any killer, especially a trained law woman, could fail to cover their tracks so badly.

"You wouldn't have thought someone in law enforcement wouldn't have done some of those things, or left so many clues or pieces of evidence," said Ben Williams.

And true-crime author M. William Phelps, who researched the case, says Tracy Fortson appears to be too smart and savvy.

"That seems like an awful stupid criminal to me right there," said Phelps.

Then there's the 1,500-pound question: How would Tracy Fortson possibly have had the strength to move Doug Benton's 250-pound body packed in a cement block weighing nearly a ton from his house to a nearby farm?

"There was a lot of speculation, 'Well, how could she have done this? She was a just a girl,'" said D.A. Robert Lavender.

Fortson was a bodybuilder, but she stands just 5 feet 6 inches tall five-foot-six and weighed 140 pounds.

"She was a strong woman, but she never had to pick him up, according to our theory of the case," said Lavender.

Investigators speculate that after murdering Doug Benton in his living room, Tracy Fortson rolled his body from the couch onto a shower curtain.

"Dragged it through the house onto the porch," said Ben Williams.

Where Fortson's pickup truck was backed up and waiting with a watering trough for animals.

"Had the watering trough already in the back and put the body in the watering trough," said Williams; filled with wet cement, then dumped it on the nearby farm.

"The main thing was no one wanted to believe that a female could get the watering trough from the bed of her truck and place it into the woods," said Williams.

But state investigator Ben Williams says all Tracy Fortson had to do was tie a rope around a tree -- and he points at the tree in a crime scene photo that shows missing bark that he claims could have been torn off by a rope.

"Tied from that to the watering trough, and all she did was drive off and the tree would have pulled the watering trough to its location," said Williams.

Author M. William Phelps is not sure he buys it.

"It's possible. Is it probable? I don't know," said Phelps.

But he says there's also another possibility.

"Tracy thinks that she was framed," said Phelps.

He points out that Doug Benton was murdered less than four months after Fortson quit her job as a deputy sheriff and filed a sexual harassment lawsuit against the sheriff's office.

Tracy Fortson continued to allege it was a set-up in a phone interview with Crime Watch Daily from prison, where she's been languishing for more than 17 years after being convicted of Benton's murder.

"I still feel that I would not be here if I had not filed that sexual harassment case against the sheriff that I worked for," said Fortson. "I just feel like that is the basis and the foundation for this whole disaster."

But investigators dismiss the allegation that Fortson was framed.

"I saw no indication of that, of any framing or set-up," said Northern Judicial Circuit District Attorney Robert Lavender.

Tracy Fortson, now 52, has already been tried twice, winning an appeal of her first conviction, only to be found guilty again at her second trial and sentenced to life for malice and felony murder, plus 10 years for arson.

"Because they said that someone tried to burn the house down to eliminate evidence," said Fortson.

But Fortson answers the next question we ask her the same way she's answered it from day one: Did you kill Doug Benton?

"No, ma'am. I did not kill Doug Benton," Tracy Fortson tells Crime Watch Daily.

Her mother Sharon has always believed her. And she has another ally, a most unlikely one: Doug Benton's mother.

"I really feel it was a frame-up," Carol Benton tells Crime Watch Daily. "I don't think she was even part of it. It makes me feel like somebody got away with the murder of my son."

After thoroughly re-examining the case from top to bottom, true-crime author M. William Phelps believes Benton's mother could be right.

"There are unanswered questions here that need to be investigated on a much deeper level," said Phelps. "An outside independent body of professional investigators should really take a look at everything that's going on here."

Tracy Fortson has already been denied parole once and is scheduled for another hearing in 2019.