Nikki McPhatter did what millions of people do every day, looking for love, trying to find the right someone. But was her guy really who she thought he was?

Vivacious young Nikki would be found shot in the head and burned beyond recognition in the charred wreckage of her torched car. Nikki was dating Theodore Manning. But she wan't his one and only. Turns out the handsome Manning is a serial Casanova.

But is this the bloody, dirty work of a bad boyfriend, or one of his jealous girls gone wild?

It's the latest chapter in a shocking tale of lust and lies that ended in the tragic May 2009 death of Nikki McPhatter when she was just 30 years old.

Nikki McPhatter joined the U.S. Navy straight out of high school.

And after returning to civilian life, Nikki's sister Latoya tells Crime Watch Daily, Nikki turned her sights from the sea to the air, working as a ticket agent for US Airways at Charlotte Douglas International Airport in North Carolina, and going skydiving every chance she got.

The single and ready-to-mingle Nikki had been looking for her "Mister Right" on an internet dating site. Among her matches, Nikki did mention Theodore Manning, who like Nikki was 30 and a military veteran. Manning served in the U.S. Air Force before taking a job at a power plant in Columbia, South Carolina. Nikki affectionately called him "Teddy," and she would drive to nearby Columbia to see him on weekends.

One of the things Nikki reportedly didn't like about Manning was his admitted weakness for other women, and his insistence on dating them all simultaneously.

Latoya says her little sister Nikki finally decided to dump the divorced father of a young daughter after dating him on and off for several months.

"She says, ''Toya, I am ending it. I'm done,'" said Latoya.

Nikki drove to Columbia to see Manning one last time, telling her sister she was just to get some stuff back from him. But Nikki didn't return as planned.

"She was supposed to come back that same day. She had to work. And she never reported to work, and I never heard anything from her," said Latoya. Latoya didn't panic immediately.

"I just kept calling her cellphone and I thought maybe she was out of town or something," which was not unusual for Nikki. "Because she did work for the airline and she would take trips."

Then Latoya gets a call from Nikki's boss saying she hasn't shown up for work for nearly a week.

"Very unusual," said Latoya. "She had perfect attendance."

Now Latoya does panic, and reports Nikki missing to the police.

Friends and family were out searching for Nikki McPhatter for three agonizing weeks before learning what became of her.

Richland County, S.C. sheriff's detectives investigating Nikki McPhatter's disappearance immediately suspected foul play. Investigators immediately look at Nikki's boyfriend Teddy Manning, but with all of his other girlfriends it's a tangled web. Police wonder if the savage killing was an act of jealous rage. But after talking to Nikki's friends and family, they zeroed-in on Teddy Manning.

"Once we were able to identify Theodore Manning and speak with him, the investigation really sort of ramped up," said Isenhoward.

Manning's phone records showed that on the day after Nikki disappeared, he had called Kendra Goodman, a 27-year-old single mother of two, one of his many girlfriends.

Kendra was about to become entangled in a sickening murder case.

Speaking for the first time in a Crime Watch Daily exclusive interview, Kendra Goodman says she arrived at Teddy Manning's home to find him doing mechanical work on a black Honda he said belonged to a friend. Kendra says Manning offered her the rims on the car. She says Manning then asked her to help him deliver the car back to his friend and give him a ride back home.

"He pulls it out of the garage, he says, you know, 'Can you follow me?' And I said 'Sure,'" said Kendra.

Kendra says they drove to a remote area where Manning asked her to wait in a church parking lot while he drove the car down a dirt road.

"And then I hear this big explosion in the background," said Kendra.

Kendra says she immediately became suspicious.

"He gets in the car and he smells like gasoline. And I just look at him," said Kendra. "His explanation was that they were back there burning trash or just burning something."

But she insists it wasn't until cops came knocking on her door that she learned the car may have belonged to Nikki McPhatter.

But Richland County Sheriff's Lt. Kevin Isenhoward says Kendra Goodman did know it was Nikki's car, and that she stonewalled investigators for a week.

Cops start to wonder if she's now trying to pin the murder on Manning to save her own skin.

"She just continued to stick to a lie, and then when you just proved to her she was lying, she'd come up with another one," said Isenhoward.

Isenhoward says Kendra also failed two polygraph tests. Why did she lie during the polygraphs?

"I didn't lie during the polygraphs. My nerves were shot. I've never done that before," said Kendra Goodman.

Lieutenant Isenhoward says that's when she cracked.

"Once she failed the polygraph test, she provided details of where she thought Nikki's car was," said Isenhoward.

He says he was horrified by what he found.

"The vehicle itself had been completely burned. The rims had even melted on the car," said Isenhoward. "When I approached the vehicle I could see a human skull inside the trunk of the car."

And that charred skull had a bullet hole in the back of it.

Kendra had driven to the scene with detectives.

"And I get out of the car, and that's the last thing I remember," said Kendra Goodman. "They said I got sick at the scene, I started throwing up."

The charred remains in the car turned out to be those of Nikki McPhatter, who was so badly burned she could only be identified by dental records.

"At that point we had enough to charge Mr. Manning," said Lt. Isenhoward.

Investigators discover something that would leave them appalled.

Police say in the hours after he killed Nikki McPhatter -- he would call up another woman to help him clean up his alleged crime -- and have sex with him. Teddy Manning had just been charged with the murder of Nikki McPhatter, one of the young Casanova's many girlfriends.

Detectives swooping in on his home immediately after his arrest found Nikki's charred remains stuffed in the trunk of her torched car in a remote wooded area in Columbia.

"We obtained a warrant and immediately went and arrested him in probably 30 minutes of finding the car," said Lt. Isenhoward.

Investigators had no shortage of incriminating evidence against Manning, including Nikki's blood splatter on a bedroom wall of his home, and surveillance footage of him trying to loot her bank account at an ATM.

"It all just ultimately matched up," said Isenhoward.

Detectives knew how Manning had killed Nikki after finding a bullet hole in the back of her skull. But what detectives didn't know was why Manning shot her and the circumstances that led up to the tragedy.

"I believe Nikki McPhatter was here to end the relationship, and it infuriated him," said Isenhoward.

So Manning shot her execution-style, investigators say.

"I felt like we had proven that this was a calculated, cold-hearted murder, pre-planned," said Isenhoward.

But Manning told detectives a very different version of how Nikki died.

"We never had a physical confrontation the entire time we talked," Manning said during questioning.

But then, Manning says, Nikki got angry.

"That she was aggressive and that she couldn't handle how he described the relationship," said Isenhoward.

"He said, 'Look, again, I want to tell you we're just "friends with benefits." I want to make that clear,'" said Theodore Manning's defense attorney Luke Shealey.

"She wanted more and that started an argument and ultimately fueled what happened to her," said Isenhoward.

"He described her as becoming very upset by this, enraged," said Shealey.

Shealey says his client told him Nikki McPhatter grabbed a loaded handgun he kept in a bag, that they struggled over it and it accidentally discharged.

"He describes the gun as going off, her dropping to the ground, kind of a slow motion thing for him," said Shealey. "Very surreal."

But Lt. Isenhoward didn't buy it.

"Nikki was shot in the back of the head," said Isenhoward. "That's not a typical injury for an accidental discharge, or even, you know, a struggle over the gun. It's an indication of an all-out murder."

Lt. Isenhoward says that instead of calling 911, Manning tried to cover up Nikki's killing.

"The question he had to ask himself was, 'If I call police right now, are they going to believe me?'" said Shealey. "And he made a poor decision, didn't call police. Called another girlfriend."

Kendra Goodman, who Manning accused of being the actual mastermind of the cold-blooded disposal of Nikki's body.

"His testimony was that she kind of guided him through disposing of this incident and kind of hiding the fact of it to get him through this daze," said Shealey.

"That's a lie," said Kendra Goodman. "That's all a lie."

Kendra claims in our exclusive interview that she didn't know Manning had killed Nikki when she arrived at the house. Kendra also says she had no idea it was Nikki's car Manning was working on when she arrived at the home.

But investigators say Kendra knew all about Nikki's killing.

"We found some receipts where Kendra Goodman and Theodore Manning had gone to a local store and purchased bleach," said Lt. Isenhoward. "We believe that was to clean up the crime scene."

Kendra denies that.

"That was for my home, just my cleaning supplies for my place," said Kendra.

But Isenhoward says Manning and Kendra did more than buy bleach: He says security video is a damning piece of evidence against Kendra. Cops claim it captures Manning trying to use a debit card he'd stolen from Nikki's purse at a bank ATM. Detectives say Kendra was right there with him, sitting in the car.

"I didn't know what card he had," said Kendra.

The detective says Manning gave Kendra $80 cash he'd also stolen from the purse, as well as the purse itself.

"I didn't know it was her money," said Kendra, claiming she didn't know it was Nikki's purse either.

And Lt. Isenhoward says Kendra and Manning did something particularly appalling just hours after cremating Nikki's body:

Did she have sex in the crime scene?

"In the house, later that night, yeah," said Kendra. "After everything."

That made it appear to Lt. Isenhoward that Nikki McPhatter's shooting was a sick "thrill-kill."

"It's conniving, cold-hearted, unbelievable that someone could do that to a person and then be excited by it," said Isenhoward. "Heartbreaking."

Manning was tried for murder, and Kendra as an accessory after the fact

"I felt like we had a good case and we proved it," said Isenhoward.

But the jury shocked Nikki McPhatter's friends and family, as well as police and prosecutors, when they found Theodore Manning guilty of only voluntary manslaughter.

"I just respectfully disagree with their ultimate verdict," said Isenhoward.

"They didn't find him guilty of murder. They didn't go with self-defense either," said defense attorney Luke Shealey. "But they went with something in between, saying that this was a heated exchange, something that was in the heat of the moment, a very emotional killing."

"But luckily the conviction that they did hand down also carried a pretty stiff prison sentence," said Lt. Isenhoward.

Manning was sentenced to 30 years in prison.

"In South Carolina you have to serve 85 percent of your sentence, so he will be there for a while," said Isenhoward.

Kendra Goodman was convicted of being an accessory after the fact, but served less than two years in prison after cooperating with police and testifying against Teddy Manning.

"My personal opinion is that Kendra Goodman should have served a lot longer in prison," said Isenhoward.

Kendra Goodman admits she made an error of judgment but is glad she helped convict Manning of Nikki's killing.

"There was no plea deal on the table. I didn't do it for a plea. I didn't do it to try to lessen a sentence or anything," said Kendra. "I did it because it was the right thing to do."

And Nikki's sister Latoya says she accepts the jury's decision.

"My sister didn't have a voice, so I felt like justice wasn't completely served, but served to the best of their ability without a person to speak for themselves," said Latoya.

Latoya also says she forgives Teddy Manning and Kendra Goodman.

"Hating you is not going to take the pain away," said Latoya. "Hating you is not going to heal me any quicker. Hating is not going to mend my broken heart. So I forgive you."

Kendra broke down when she heard that.

"I still think about Nikki's family and what they deal with, so I can't even begin to imagine what they're going through, but yeah, every day, and I am still beating myself up," said Kendra Goodman.