A real-life Utah murder case becomes a TV murder mystery on Sunday when "On the Case with Paula Zahn" goes inside the 2009 killing of retired BYU professor Kay Mortensen.
And the hour demonstrates just how wrong the police and prosecutors were.
This case was big news in Utah, but it wasn't splashed all over the cable news networks so viewers who tune in to Investigation Discovery may not know how it turns out.
"The case caught our attention because of its complexity," said executive producer Larry Israel. "We are drawn to stories that have strong emotional elements involving dynamic personalities, and this case certainly had them."
Mortensen's son and daughter-in-law, Roger and Pam, told police they arrived at the BYU professor's home to find the killers still in the house. Remarkably, the men let them live.
But Payson police and Utah County prosecutors became suspicious of Roger and Pam Mortensen's story and charged them with the crime. After months in jail and on the eve of their trial, the real killers were found and the couple was exonerated.
It's chilling to hear the Mortensens talk about what it was like to be wrongfully accused. You can hear the emotion in Pam Mortensen's voice when she talks about how "tears rolled down my eyes to know this was finally over."
Perhaps the most remarkable thing about this hour of "On the Case with Paula Zahn" is that the police and prosecutors agreed to on-camera interviews. And they own up to their mistakes and apologize.
"The [county] attorney's office and investigators were incredibly forthright about how they made the decision to arrest of Roger and Pam Mortensen," Israel said. "They were equally as passionate about how sorry they were that the conclusions they reached were, in fact, completely wrong."
Timothy L. Taylor, the chief deputy in the Utah County attorney's office, said, "I felt horrible that we had made a mistake," adding that he has "done a lot of soul searching" about the case.
"It was a lesson for me that has really opened up my eyes. And we're going to make sure that, hopefully, we're going to do a better job in the future."
And "On the Case" serves as a cautionary tale for police, prosecutors and the public.
"I think the lesson of this story is that circumstantial evidence can be incredibly deceiving at times," Israel said, "and all of us have to be careful about not rushing to judgment."
"On the Case with Paula Zahn"
The report on the Kay Mortensen murder case, titled "Bound by the Truth," airs Sunday at 8 and 11 p.m. MDT on the Investigation Discovery. That's Channels 271 and 748 on Comcast; Channel 285 on DirecTV; and Channel 192 on Dish.