Unidentified DNA complicates investigation of murdered police dispatcher Dawna Natzke

Dawna Natzke, 46, was starting her life over in Hot Springs Village, Arkansas after her husband of 20 years blindsided her with divorce papers.

But Dawna seemed to be picking up the pieces, and a big part of that was taking a job as a dispatcher for the local police department.

"Everyone, every policeman just loved her," said Dawna's mother Doris Smith.

"I don't think she had an enemy or person that didn't like her," said Dawna's son Ronnie Moeller.

Yet Dawna's family says there was still an empty hole in her heart.

"She went through 20 years of being with someone that she loved. I think she wanted to kind of find that again," said Dawna's son Arin Natzke. "She just didn't want to be lonely.

But Dawna's lonely days were about to be over. To everyone's surprise the soon-to-be divorcee shows up in town on the arm of Kevin Duck, a man 18 years younger than Dawna.

"She loved the attention because she wasn't used to it, and that was her attraction to him," said Doris Smith.

Dawna's mom Doris says her daughter often asked her to tag along on her dates with Duck.

"She would say 'Mom, pick me up and take me to so and so, I'm supposed to meet Kevin,' so she'd go with me," Doris tells Crime Watch Daily.

"We just kind of went with it because we were just trying to make our mom happy," said Arin.

But Dawna's happiness is short-lived. Kevin Duck's once-loving affection suddenly morphs into evil jealousy.

"He was always with his hand on her leg, rubbing her back, snapping her bra, very inappropriate," said Doris.

"To be that protective and that handsy with her was concerning," said Ronnie.

Dawna begins going out of her way to avoid Duck.

"Her attitude toward him changed right then," said Doris.

There was even gossip swirling around the village that Dawna had started dating a cop she worked with at the police department. Everyone was expecting Dawna to dump Kevin Duck once and for all. But he wasn't about to let that happen.

"She came home from work and he was moved in," said Doris.

Doris says Dawna was furious. Her divorce wasn't even final yet, and Duck moved into her home without asking.

"She was appalled, but he wasn't about to move out because he had given up his townhouse," said Doris.

Kevin Duck tried to win Dawna Natzke over by showering her with lavish gifts. He even bought her a car.

"I felt that Dawna was smart enough that she'd see through him too," said Doris.

But for some reason, to everyone's surprise, Dawna doesn't throw him out.

"In the back of my head, I'm saying, you know, there's just something not right. The whole situation just was off to me," said son Brandin Natzke.

It appears Dawna's had a change of heart and wants to make the relationship work. So when the couple gets invited to a Christmas party, Dawna happily accepts. Then, at the last minute, Dawna asks her mother to come along.

"When they picked me up, there was not good vibes between them," said Doris. "She was almost ready to cry. And I noticed her nose was red. When she's upset, her nose got red."

At the party, Dawna and Duck both toss back a few drinks, but neither appeared to be in a festive mood.

"I thought 'Well this is strange,' because when they were together, he was being very attentive, but that night, they were not attentive," said Doris.

Around 10:30, Doris says, she looked around the party and was shocked to find both Dawna and Duck were gone.

"Dawna's purse was still there, and I said 'Well, Dawna's glasses and her cigarettes and everything, and my credit cards were in her purse.' Dawna would never have left that purse," said Doris.

Dawna had never abandoned her mother before, and would never leave without at least a goodbye.

A worried friend calls Dawna to make sure she's OK. A little later, a strangely worded text comes back from Dawna's cellphone, that she took a pain pill and was "tore up."

Everyone goes to bed believing Dawna Natzke is fine. But when the sun rises the next morning, so does a disturbing mystery.

"I woke up at like 5:45 a.m., sometime roughly when my mom would be going to work, and I saw her car out on the driveway after the Christmas party," said Brandin.

A friend then spots Dawna's car speeding through the village toward her office.

"People saw it driving roughly around 6 a.m. that morning," said Brandin.

But moments later Dawna Natzke and her car both vanished.

"And within five minutes she was gone," said Doris.

A police dispatcher is missing after leaving a Christmas party abruptly on the night of December 21, 2011 with her much-younger boyfriend Kevin Duck. Was she running away from her problems, or did someone make her disappear?

"I never saw her again," said Dawna Natzke's mother Doris Smith.

Dawna's mother and her three sons were worried sick, because Kevin Duck isn't Prince Charming. He's a real-life monster.

"I had concerns for my mom's safety the second I knew she was with Kevin," said Dawna's son Ronnie Moeller.

Kevin Duck had been arrested for assaulting both his ex-wife and a former girlfriend. He had even beaten his 2-year-old daughter savagely with a PVC pipe.

"Everyone knew how he treated his own daughter," said Doris.

"I was playing scenarios in my head, and I knew that he was one of the last people that were with her," said Dawna's son Brandin Natzke.

Dawna's sons begin searching desperately for their mom.

"I started calling my mom's closest friends, seeing if I could get ahold of her," said Ronnie.

Adding to their concern, Dawna's best friend tells them she got a cryptic, misspelled text from Dawna saying that she left the party because she was "tore up" after taking a pain pill. But the friend says she found it strange because Dawna never texted her. She usually just called.

"She wouldn't leave town or hide someplace without me or my brother's knowing. We would know what was going on," said Ronnie.

"In my head, in my heart and my mind, I just knew it was Kevin," said Brandin.

Brandin tracks down Kevin Duck, looking for answers.

"I asked him what time they got home, and he said 10:30/11, and I remember it just kind of clicking in my head like, 'No,' like, 'I know you didn't, because I was up till midnight,'" said Brandin.

Now Dawna Natzke's sons are in a panic. They head straight to the Hot Springs, Arkansas Police Department where Dawna worked as an emergency dispatcher.

Cops aren't just worried about their co-worker -- they suspect their friend is the victim of foul play.

"Having done this for 21, 22 years, the bells went off," said Garland County Prosecuting Attorney Michelle Lawrence.

Prosecuting attorneys Michelle Lawrence and Joe Graham say cops went back to where the mystery all began: that party where Dawna and Duck were last seen together. It leads them to a woman who lives a few doors down. She told police she heard something that night that still echoes in her head.

"She heard what she called just a blood-curdling scream that she described as a man in a fit of rage, succeeded by a car door and then peeling tires coming out of there," said Garland County Chief Prosecuting Attorney Joe Graham.

Cops were wondering if Duck's violent behavior has escalated to murder.

"All of the signs pointed to Kevin Duck from the very beginning," said Michelle Lawrence.

But Duck maintains he's innocent, telling police he was sleeping, and when he woke up, Dawna and her car were gone.

"There was no proof that it was Kevin, but who else could it have been?" said Doris.

Days pass and still no sign of Dawna Natzke. But this case is personal for the Hot Springs Police.

"Every one of the policemen just wept when she was missing," said Doris.

"She was one of our own. So I think that motivated law enforcement to turn over every rock in the investigation," said Michelle Lawrence.

Finally, a possible break: an emergency call came in from a park ranger reporting a car fire -- it's the car Kevin Duck gave Dawna.

"The flames were still going at the time the Forestry Service found it, but it was completely engulfed in flames, and they just let it burn out at that point in time," said Joe Graham.

"It was torched. It was completely burned to a crisp," said Lawrence.

When the flames finally die down, investigators carefully sift through the ashes, expecting to find Dawna's body inside. But there's no one in the car.

"At that point in time, as a law enforcement individual, you go to 'Something's not right here, something doesn't make sense here,'" said Lawrence.

Is it possible Dawna Natzke torched the car to throw Kevin Duck off her trail in a desperate attempt to escape from him? Or was the fire set to cover up a horrible act of violence?

"You want to have hope and you want to have faith that they're going to find her, but once you see something like that, I mean, you know that there's a reason that that car was burned, you know that there's a reason they were trying to dispose of it," said Brandin Natzke.

Cops immediately launched a ground search in the area surrounding the burned car.

"Word got out pretty well about it, people coming out to help," said Graham.

Hours pass, then days. Hopes of finding Dawna alive begin to fade.

"You just know that mom's out there somewhere, and it's cold outside and there was days that it was raining," said Brandin. "I was just sitting there, just thinking like 'I don't need to be here right now, I need to be out there, I need to be trying to look for her, I need to be trying to find her.'"

"We went on for nine or 10 days with very little sleep and always on edge, always wondering where mom was. My biggest fear was we never would find her," said Ronnie.

Then one of the most unlikely people volunteers to join the search.

"Luther Duck, who is Kevin Duck's father, had been one of the persons who showed up to volunteer to do the search," said Joe Graham.

Duck's dad tells cops he believes he knows exactly where to find Dawna.

"Luther had volunteered to search a certain portion, and his reasoning was this was a portion that was very close to where the childhood home of Kevin Duck was, where Luther Duck had raised him," said Graham.

Luther specifically wants to search a pond that he used to take Kevin to when he was a young boy.

"Kevin spent a lot of time there. He said 'If he's killed her, that's where she is,'" said Graham.

And there in that pond, officers find pieces of Dawna's body scattered along the shore.

"They found her body, deceased. She had been there for some time. My understanding was that it was a very gruesome scene," said Michelle Lawrence.

Dawna's remains paint a painful picture. The coroner determines she was brutally beaten -- but that's not what killed her.

"From what the medical examiner told us was that she did receive blunt-force trauma, but at the time that she was dumped into the pond, she was still alive, and she drowned," said Lawrence.

"It was something that just takes your breath away," said Arin Natzke. "It's just something that you just won't believe, like, it would happen in a nightmare."

Dawna's boys and the cops are more convinced than ever that Kevin Duck is the killer.

"We had intuition that Kevin Duck was the suspect, but of course we have to prove it beyond a reasonable doubt," said Michelle Lawrence.

Dawna's naked body was so badly decomposed, cops had little to work with. Luckily they find her clothes strewn throughout the forest. And on her bra there's DNA evidence that cops hope will confirm Kevin Duck is her killer.

"There was a mixture of DNA. Part of the mixture was Dawna, which is completely expected on her bra. The other part of the mixture was a male profile," said Graham.

"There was no doubt in my mind that Kevin had killed my mother," said Brandin.

But hold on: the results are in, and cops are stunned.

"It was not his DNA," said Joe Graham.

There was little doubt in anyone's mind who had brutally beaten and murdered Dawna Natzke. Dawna was last seen leaving a party with Kevin Duck. A neighbor reported hearing a blood-curdling scream at the exact time they left the party. Duck blatantly lied to Dawna's son about what time he got home. And Duck's own father even led cops to Dawna's body, scattered around a remote pond in the forest.

But prosecutors had one big problem with a key piece of evidence: the DNA found on Dawna's bra at the crime scene.

"There was a mixture of DNA," said Joe Graham.

Prosecutor Graham won't be specific as to what kind of male DNA was found, but tests reveal one thing.

"We had collected samples from Kevin Duck to have analyzed and it was not his DNA," said Graham.

If it's not Kevin Duck's DNA, whose is it? Prosecutors tell Crime Watch Daily the sample doesn't match anybody in the national DNA data system. So the question is, Who was with Dawna when she was murdered?

"There's no doubt that whomever's DNA is on that brassiere had something to do with this crime," said Kevin Duck's defense attorney Brian Johnson.

Attorneys Brian Johnson and Clay Janske represent Kevin Duck. They say that mystery DNA, along with some clothing found near the crime scene, prove Kevin Duck didn't do it.

"There was also some clothing that was found on a barbed-wired fence out there that they could not match back to any of Mr. Duck's clothing," said Clay Janske.

Kevin Duck maintains he was at home sleeping the night Dawna Natzke was murdered, but he tells detectives he remembers Dawna saying she was going back to the party after he went to bed.

"Dawna was going to head straight back to the party, get her mother and take her back to her vehicle, or stay at the party for a little bit longer," said Joe Graham.

But Dawna never made it.

"There was obviously another person that came into contact with her," said Clay Janske.

Investigators looked at Dawna's soon-to-be ex-husband Todd Natzke.

"I mean obviously you've got a divorce going on. Apparently Todd has sued Dawna's mother about some money issues, and so we certainly thought that Todd would be a suspect," said Janske.

But Todd Natzke has an alibi, and it's rock-solid.

"Todd Natzke had a completely airtight alibi," said Graham. "One of their children was with him, his then-girlfriend was with him during all the times that this could have happened."

Then Kevin Duck makes a jaw-dropping accusation, pointing the finger right at Hot Springs' top cop.

"Kevin had also heard that the chief of police was having some type of relationship with Dawna Natzke," said Brian Johnson.

Remember Dawna was a police dispatcher and worked with Chief David Flory at the Hot Springs Police Department.

"We had been approached by a couple of police officers that were under the chief's control who had said that they believed that there was an affair going on," said Janske.

Police Chief Flory vehemently denies the accusation and voluntarily submits his own DNA sample.

"They did a DNA test and it didn't match," said Brian Johnson.

For months the DNA remains a mystery, and so does the identity of Dawna's killer. But her co-workers refuse to give up until they find the real killer.

"This one was very personal for the Hot Springs Village, this was one of their dispatchers, this was one of them. Definitely paid attention to it to make sure that justice would be done," said Graham.

Then an unexpected witness comes forward: Kevin Duck's ex-wife. She tells detectives a story that sends chills down their spines, revealing an eerily familiar story about how Kevin Duck brutalized her and then left her for dead.

"He had beaten her up, taken her out into the middle of the woods and just left her," said Graham.

Now investigators can't help but wonder if their initial suspicions were correct.

"All of the signs pointed to Kevin Duck," said Michelle Lawrence.

But could they prove it?

"They began interviewing anyone and everyone in the timeline from when Dawna had last been seen," said Lawrence.

"One of the people who had worked with him said they'd noticed him checking various things on his work computer, the weather, the Greyhound bus schedule to Canada, a few other things that just struck him as odd," said Graham.

"They interviewed the employer for Kevin Duck who articulated that that morning he was supposed to be at work at 8:30 he did not show up until about 10:10 a.m., which was late for him," said Michelle Lawrence.

So where was Duck the morning after Dawna disappeared? On a hunch cops subpoena cell tower records in the area to track the location of Duck's phone location during the hours Dawna went missing. The results were not good for Duck.

"Cellphone analysis showed that he could've been within 200 yards from where the car ended up burned out on the very remote national forest road," said Graham.

"Shortly thereafter they located his phone being next to the pond where Dawna Natzke's body was eventually found," said Lawrence.

"Kevin Duck was clearly the person who had killed Dawna Natzke," said Graham.

Cops arrest Kevin Duck for the murder of Dawna Natzke.

"Kevin Duck was charged with murder in the first degree. The only thing higher in Arkansas is capital murder," said Joe Graham.

But prosecutors know proving the case is going to be difficult.

"It was a circumstantial case, nobody saw him do it," said Lawrence. "We have a neighbor who saw that there was some type of scuttle. Then you have the employer of Kevin Duck. To top it all off you had these phone records that basically put him in a certain place near Dawna and near her destroyed car at the times when it would have happened."

But what they don't have is answer to that critical question: Whose DNA was on Dawna's bra?

"At the very least it tells you that somebody else was present there. The real physical evidence of this case points to somebody besides Kevin Duck," said Brian Johnson.

Despite the mystery DNA, Kevin Duck is charged with murder. His trial last four days, and after just four hours of deliberation, the jury is back with a verdict.

"He was found guilty of murder in the first degree," said Lawrence. "No chance for parole at all."

The mystery of the DNA may never be solved. Did somebody help Kevin Duck kill Dawna Natzke, or was the DNA planted to throw cops off Duck's trail?

"I think he genuinely feels bad for Dawna Natzke's family, but he also still maintains that he is innocent of the crime," said Johnson.

But Dawna's family doesn't want to hear it. Her sons believe without a doubt it was Kevin Duck who killed their mom and robbed them of a lifetime of memories.

"I'm going to have to go through my wedding without my mom. I'm going to have to go through the birth of my children without my mom," said Brandin.

"Getting my first big job, telling her like, 'Hey mom, you won't believe what happened,'" said Arin.

"All these milestones throughout my and my brothers' lives and events, she's just not there," said Ronnie. "She's just gone."

And Dawna Natzke took a big chunk of her mother's heart with her.

"It wasn't right because she wasn't supposed to go first, so. I really miss her. Always," said Dawna's mother Doris Smith.

During the sentencing hearing phase, Duck's brother testified that Kevin became very violent when he was 7 years old, even faking his own suicide by firing a shotgun in his bedroom.

After sentencing, while Duck being transferred back to jail, the convicted killer told reporters "I think y'all made a mistake."