What happened to Mike Sisco and Karen Harkness? Details explored ahead of Dateline on NBC

Dana Chandler, the prime accused in the murder case of the Kansas couple Mike Sisco and Karen Harkness, has been found guilty in her third court trial on March 7, 2025. Mike and Karen were found dead in their bedroom in 2002. After two decades of search for the killer and three criminal trials later, the police have made some progress in the case.

The Dateline episode set to be aired on NBC on April 4, 2025, at 9/8c will bring viewers the full case of what happened to Sisco and Harkness and how Chandler was arrested on suspicion of their murder.

The synopsis of the episode titled Deadly Obsession reads:

"Kansas couple Mike Sisco and Karen Harkness are found dead by their parents before a family fish fry in 2002. A years-long search for evidence and three criminal trials over two decades reveal strained dynamics within one victim’s family."

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What happened to Mike Sisco and Karen Harkness?

Mike Sisco was Dana Chandler's ex-husband. The couple were married for several years and even had two children together. However, their marriage turned sour in the 1990s, and they decided to part ways.

The divorce process was a tedious four-year affair for the two. At the end of it, the court awarded Mike Sisco full custody of the children while ordering Dana Chandler to pay child support, as per an article by Oxygen dated September 2, 2022.

After the divorce, Mike Sisco began dating Karen Harkness, but things turned difficult for the new couple due to Dana Chandler's continued obsession with her ex-husband. She made frequent calls to him and also to Harkness and, in the spring of 2002, even broke into the couple's house.

But things went too far on July 6, 2002, when Sisco and Harkness went to the Sac and Fox Casino, where they gambled and had their dinner. They were on their way back home the next day when they stopped for coffee at a gas station at 1 AM. That was the last time the couple was seen alive, as per a report by The Topeka Capital-Journal dated August 6, 2022.

On July 7, 2002, Harkness' parents and a couple of their friends showed up at their residence. They were surprised to notice that the garage door was open and Sisco's SUV was parked in the driveway. When they went around the house, they discovered that the sliding glass back door was open.

That was when they sensed that something was off. Karen Harkness' father, Harold Worswick, entered through the door and began searching for his daughter and her partner. To his horror, he found Harkness and Sisco in the basement, naked and dead. They seemed to have died from 12 gunshot wounds, as per The Topeka Capital-Journal.

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Dana Chandler was convicted for the murder of Sisco and Harkness

Mike Sisco and Karen Harkness were found dead on July 7, 2002 (Image via Pexels)

In 2011, ten years after the Kansas couple met a brutal end, the police were able to convict Dana Chandler, Sisco's ex-wife, for the murder. However, in this first trial, the ruling was overturned in a 2018 appeals case with the Kansas Supreme Court on the basis of prosecutorial misconduct, as per a CBS News report. Chandler took the stand again in 2022, but that trial fell through as the jurors were not able to reach a verdict.

A third trial was conducted on March 7, 2025. In this trial, a Pottawatomie Co. jury found Chandler guilty in the 2002 double homicide of her ex-husband, Mike Sisco, and his fiancée, Karen. Dana fired her lawyers and chose to represent herself in her third trial.

Although the guilty verdict has been declared, Dana Chandler is set to be sentenced for the murders at a later date.

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Catch tonight's Dateline episode for more about the case of Dana Chandler.