The story of Lori Kay Soares and her husband Mark Hacking is the stuff of nightmares.

Lori was murdered in cold blood in her sleep by her husband Mark, and no one could believe the incidents that had transpired between the two on a fateful day in July 2004.

Mark and Lori were high school sweethearts. They loved each other and Lori's family often looked at the two and wondered how they had gotten so lucky. Mark was like a son to them.

Lori was an adopted child. Thelma and Herald Soares had taken her in after her parent's divorce in 1987. The family had met in Brazil and, after the adoption, they relocated to Orem, Utah.

Lori met the love of her life as she attended Orem High School near Salt Lake City. It was like sparks flew the very first time they saw each other on a trip with their friends to Lake Powell, Utah in 1994.

The rest was history.

Lori and her husband Mark Hacking were happily married for five years and were together for 10 before she disappeared (Twitter)

The two had been together for a decade before Lori had found out that she was pregnant.

Everyone in their family was overjoyed by the news—they had so much to look forward to.

The couple was also moving to Chapel Hill, North Carolina where Mark had enrolled in medical school.

Thelma, Lori's mom, recalled thinking that it would be difficult for them, especially Lori to have a baby and be the one working.

The disappearance of Lori Hacking

On July 19, 2004, a frantic Mark Hacking called 911 saying that his wife had gone missing.

She had gone for a jog to the Memory Grove and City Creek Canyon, following which she was supposed to go to work but never showed up.

She had also not come home.

It was a ritual for her to go for a jog and then head to work but, because she hadn't shown up, Mark had been worried. He had called her colleagues and friends and they had no idea where she was. Her car was found parked at the entrance of the park but Lori was nowhere in sight.

Her friends and family knew that Lori wasn't the kind of person who would just run away, not with so many great things coming her way. The authorities and everyone else came to the conclusion that she had been abducted.

Detectives saw what no one else did

There were certain things that made the detectives on the case very suspicious at the very beginning, especially SLCPD lead detective Kelly Kent.

Like the recent case of Colorado killer Chris Watts, who went on TV to grieve about his missing wife and kids when in reality he had butchered them, Mark also went on TV, urging everyone to help him look for his wife.

He seemed heartbroken and distraught.

The news that Lori was pregnant also caught the attention of the public.

A national search ensued, but with no results.

By now, the police were conducting a two-prong investigation—abduction and possible homicide.

Although Mark had cleaned up well, there were certain things that made the detectives on the case very suspicious, especially SLCPD lead detective Kelly Kent (Twitter)

Meanwhile, Detective Kent started adding two and two together.

There were a number of circumstantial clues in the couple's home.

She found Lori's purse just sitting at home, with her wallet inside. Mark explained that since it was a jog she hadn't taken her purse.

Secondly, Kent found that the bathtub was squeaky clean and smelled like bleach. The sheets on their bed were washed and crisp like they had just been bought and the bed made recently. There was a bouquet of flowers sitting on her dresser, indicating that there was something going on between the two and Mark may not have been telling her the whole truth.

Her ring was found sitting in her jewelry box.

Something was wrong here, the detectives thought.

Digging further, they also found that Mark had just bought a new mattress and, curiously, Mark also knew when the community garbage grid was emptied. They found that the box springs also didn't match the mattress, which indicated that this was done recently.

They also found a hunting knife in his drawer that had some blood on it. Mark told them it was from a recent hunt.

Kent, however, was convinced that he had killed her and dumped her body in the trash.

The lies unravel

One night during the investigation, Kent got a phone call from an emergency operator stating that someone who had matched the description of Mark was seen running around naked in a motel nearby.

When they went to check, he was seen butt naked and hysterical—but the cops saw that he still had his flip flops on and that gave it away. He was clearly seeking sanctuary somewhere and his best bet was mental health facility.

The bigger shock was yet to come.

The police checked in with the University of North Carolina and the University of Utah and what they found out shocked them—he wasn’t enrolled at Chapel Hill and they did not have any record of him, at all.

He hadn't even graduated. He had managed to fake everything.

Lori had found out about this and had wanted to end their relationship.

This is when Mark had shot her with a rifle in her sleep, killing her and their unborn baby.

Lori's body was found on October 1, 2004, in a landfill after the police carried out a search for many months.

The landfill was about 10 acres and the investigators had to hand search the trash as well as use cadaver dogs. They found human remains in the trash.

Finally, a jaw was found and the teeth belonged to Lori Hacking.

Mark was charged with first-degree murder and got a sentence of six years to life for killing his wife.

She was 27 years old when she died. He pled guilty in exchange for dropping the other charges.

What pushed him over the edge to commit this crime, and what was his true motive?

To learn more about Lori Hacking's murder, watch Oxygen's new series 'A Lie to Die For' premiering on Sunday, June 23 at 8pm ET/PT.

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