Dave thought his ex-girlfriend was stalking him for years. She had actually been murdered.

Dave Kroupa thought joining an online dating website would help him meet new people. 

He was recently separated from his long-term partner, Amy Flora, with whom he shares two children. And he had just relocated to Omaha, Nebraska to start a new job as a manager at an auto repair shop. 

New in town and hoping to make new connections, Dave thought online dating was a step in the right direction. 

Little did Dave know, when he first signed up to the website, that it would put him straight into the path of a duplicitous cold-blooded killer. 

The first person Dave met online was a woman named Shanna Elizabeth Golyar who went by "Liz". 

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Liz was also a single parent, and they hit it off immediately. And by the fourth date they were sleeping together. Dave had been upfront with Liz about not wanting to jump into anything too serious and she seemed to be on the same page as him. 

After about six months of the couple casually dating each other, Dave met another woman. Cari Farver, also a single parent, brought her car into Dave's work for maintenance and he found himself immediately attracted to her. 

"I don't want it to sound like one of them goofy movies or what not, but when she wandered in and I saw her I was like 'hey, this is a good-looking woman'," Dave told the Strictly Stalking podcast this month. 

After she came into his work for a second time, the pair went on a date. When they went back to Dave's apartment afterwards, Cari told him she wasn't looking for anything serious.

However, just as things were heating up, Liz turned up. She wanted to collect some things she'd left there.

Dave explained the situation to Cari, and she understood but decided to call it an early night. Dave buzzed Liz in and let Cari out, and the two women passed each other in the hall. It was a brief encounter, but one that would change the lives of the three people involved forever. 

On November 13, 2012, after they had been dating for just two weeks, Dave received a text from Cari saying she wanted them to move in together. 

When Dave replied to say it was too soon, Cari immediately became aggressive. 

"Fine. I hate you. I'm dating someone else. I don't want to see you anymore. Go away," her text read. 

Around the same time, Cari, who was diagnosed with depression and bipolar disorder in her 20s, started sending strange messages to her family and friends. 

Cari Farver. Image: YouTube.  

She told her mother she had moved to Kansas for a new job and wouldn't answer phone calls. As the weeks and months went on, she missed a bunch of important family events including her own son's birthday. 

Dave continued to receive threatening and abusive messages from Cari, with the main focus of the messages being Liz Goylar, the woman she had briefly passed in the hallway that night. 

Liz contacted Dave and told him she was also receiving messages and that someone had spray-painted 'Whore from Dave' on her garage. 

The harassment of Dave escalated to the point that he was sure someone was watching him. 

"On one specific occasion, I was sitting in my La-Z-Boy with my feet up, watching TV, trying to relax, and it's nighttime and I get a text saying, 'I see you. You're sitting in your chair with your feet propped up, wearing a blue shirt.' And those things were true," he told ABC News.

Dave and Liz, who were still seeing each other casually, would often both receive harassing text messages while they were sitting beside each other on the couch. 

In January 2013, Dave noticed Cari's car in a parking lot. He took a photo and sent it to the police. They searched the car and were only able to find one fingerprint, which didn't match Cari or anyone in the FBI's database. 

Meanwhile, Cari's mother was desperately searching for her daughter with little help from the authorities who believed she had just left on her own free will. 

The harassment continued to escalate with Cari threatening to kill Liz and sending Dave a photo of a woman tied up in the boot of a car. 

Then, in August 2013, Liz's house burnt down and her two dogs, cat and pet snake died in the fire. 

In 2015, two and a half years since anyone had seen Cari alive, Detectives Ryan Avis and Jim Doty, of the Pottawattamie County Sheriff's Office in Council Bluffs, Iowa, took on the case. 

They were immediately suspicious of Liz, who had only had that brief encounter with Cari but now seemed to be the main focus of her harassment campaign. 

The two detectives looked through the case file and the contents of Liz's phone - which she had agreed to allow the police to download during the original investigation in 2013. On the phone, they found a photo of Cari's car, taken weeks before the police found it, and the photo of the woman tied up in the boot of a car. They also matched the fingerprint found in the car to Liz. 

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On December 4, 2015, Liz walked into the police station to file a complaint against Amy Flora, Dave's ex, who she now believed was behind the harassment. The next day, she said she was shot in the leg while walking alone at night. She claimed Amy was the shooter. She had already reported Dave's gun as missing. 

As part of their investigation into the case, the detectives asked to once again download the contents of her phone, which she once again agreed to. 

On the phone they found evidence that Liz had set up 20 to 30 fake email addresses and was using an app to schedule messages ahead of time. 

That's when the detectives came up with a plan.

They told Liz they believed her and asked her to reach out to Amy to see whether she would incriminate herself. Liz sent Amy an email and immediately started forwarded emails to the detectives that were supposedly from "Amy" confessing to shooting Liz. In further emails, "Amy" also confessed to stabbing Cari "three to four times" and stuffing her body into a garbage bag. 

While Liz was brought in for questioning, police searched her apartment and found some of Cari's possessions including a digital camera and camcorder. 

Finally, on December 22, 2016, four years after Cari vanished, Liz was arrested and charged with first degree murder. 

That's when Dave realised the woman he was currently dating was actually the person who had been stalking him for over four years. Liz had burnt down her own house, killing her pets, and had shot herself in the leg. And Cari had been dead this whole time. 

"I don't think it even sunk in when I heard her pronounced guilty," Dave said on the Strictly Stalking podcast this month. "It was surreal. If I read this book, I wouldn't believe it." 

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