A family fish fry took a tragic turn when a Kansas couple was found dead in their home just before the festivities were set to begin.
It would take decades, and multiple trials, to get justice, leaving one surviving family member fearing for her own safety as the case took one surprising twist after another, according to an all new Dateline, airing Friday at 9/8c on NBC.
What happened to Mike Sisco and Karen Harkness?
The episode, titled “Deadly Obsession,” focuses on the harrowing double homicide of Mike Sisco and Karen Harkness.
”Kansas couple Mike Sisco and Karen Harkness are found dead by their parents before a family fish fry in 2002,” reads an official synopsis for the episode. “A years-long search for evidence and three criminal trials over two decades reveal strained dynamics within one victim’s family.”
Just before their deaths, the couple’s romance had been in full bloom as they celebrated the Fourth of July holiday with those close to them.
“They were especially happy that night. They were in love,” Karen’s friend Linda Briden recalled in a preview of “Deadly Obsession.”
But just days later, in the early morning hours of July 7, 2002, the couple was killed in bed inside their Topeka, Kansas home.
“I thought that I heard gunshots and even though it was July, they didn’t sound like firecrackers,” neighbor Michelle Delgado told Dateline correspondent Andrea Canning, who reported on the case.
The slain couple was later discovered by their parents just as the family was gearing up for a celebration together.
“She’s downstairs and she’s dead,” a male caller can be heard telling a 911 dispatcher in the preview.
The double homicide sent shockwaves through the community.
“Who would want to kill Mike and Karen? And even more baffling, why?” Canning asked in a voiceover in the preview.
Son suspects “psychopath” could have played role in killing
Karen’s son Chad Harkness had his own suspicions about who may have had it out for the pair.
“When he told me what had happened, I said, ‘This is that crazy psychopath,’” he told Dateline of one suspect who played a central role in the investigation.
But it would take years and help from the daughter of one of the victims before police could make an arrest.
“I was recording our conversations,” Mike’s daughter Hailey Seel said of how she was able to help.
Mike Sisco’s daughter fears for her “safety”
Even after a suspect had been taken into custody, the case was far from over. It would take multiple trials to arrive at a definitive conclusion, and as justice appeared elusive, Seel began to wonder whether her own life could be in danger.
“I was afraid for my safety, for sure,” she told Canning.
Along with Hailey Seel and Chad Harkness, Canning also spoke during the two-hour broadcast with Mike’s mother Carol Sisco, his sister Cathy Boots and his brother-in-law Mark Boots. Karen’s daughter Erin Harkness Sutton also added commentary, along with former Topeka Police Sgt. Richard Volle and Shawnee County District Attorney Mike Kagay.
To find out how the case finally came together, watch Dateline Friday April 4, 2025 at 9/8c on NBC or stream the episode on Peacock after it becomes available the next day.
Other Dateline mysteries this weekend
If you’re looking for even more mysteries to unravel this weekend, Dateline has you covered with two episodes of the newsmagazine on Saturday and Sunday nights.
The mystery, “The Streets of Laredo”, reported by correspondent Josh Mankiewicz, is an encore that will air Saturday, April 5 at 9/8c on NBC.
According to the official synopsis: “In the summer of 2018, the Webb County Sheriff’s Department begins investigating a string of deadly shootings targeting women in the border city of Laredo, Texas. When the lead investigator calls in reinforcements from other law enforcement agencies to help solve the case, an unexpected suspect comes to light.”
As Mankiewicz reported the terrifying race to take down an elusive serial killer on the loose, he spoke to lead investigator Capt. Federico Calderon, District Attorney Isidro Alaniz and more.
Then, on Sunday, true crime fans can delve into the mysterious disappearance of college student Mollie Tibbetts in “The Last Mile,” airing at 10/9c on NBC.
“Mollie Tibbetts, a college student home for the summer, goes missing while jogging,” the synopsis for the all new episode reads. “Her close-knit Iowa town comes together to search for her until investigators discover security camera video that reveals a critical clue.”
Mankiewicz once again takes the helm to report on the headline-making case, speaking to Tibbetts’ best friend, her cousin and the investigators who helped put the pieces of the case together.
