How a Woman's Plot to Frame Boyfriend for Murder Let a Serial Killer Continue His Spree

In 1990, Laverne Pavlinac had reached her breaking point.

Feeling stuck in an abusive relationship with a boyfriend nearly 20 years her junior, the 57-year-old woman from Portland, Ore., decided she'd go to extreme lengths to escape his orbit.

When Pavlinac heard that a young woman named Taunja Bennett had been strangled to death in her hometown, she saw the unsolved murder as an opportunity to put her boyfriend, John Sosnovske, behind bars.

So she framed him for Bennett's murder.

First, Pavlinac anonymously called investigators, claiming that she overheard Sosnovske at a bar bragging about killing the 23-year-old. Then, she said she knew Sosnovske was guilty because she was there when he raped and killed her — thus implicating herself in the false narrative.

Pavlinac's elaborate lies about the murder were enough to convince a jury that both she and Sosnovske deserved to be imprisoned for Bennett's death.

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With Bennett's believed killers behind bars, investigators put her murder investigation to rest, unaware that the real culprit was running free, continuing to kill.

In 1995, Keith Hunter Jesperson, more widely known by his nickname, the "Happy Face Killer," turned himself in and confessed to several murders across five states.

His first victim, he said, was Bennett.

On this week's episode of 20/20, ABC News explores the peculiar case of Pavlinac, and how her elaborate plot to frame her boyfriend for a stranger's murder hindered authorities from catching a serial killer.

"The greatest human tragedy is that Laverne Pavlinac derailed the investigation in 1990, and in four years, Keith Jesperson killed more women," Jim McIntyre, the Oregon prosecutor who handled the cases, tells ABC News.

The two-hour episode features conversations with several officials and family members close to the case, including interviews with Pavlinac's daughters, Bennett's sister, and Jesperson's daughter, and archived footage of Nightline anchor Juju Chang speaking with Jesperson himself.

20/20 also obtained police tapes that show just how far Pavlinac went to convince investigators that she and Sosnovske were guilty of a crime they didn't commit, even weaving unpublished details about the crime into her fictional confession.

"Just so many bad things that happened in [Pavlinac's] life that I think, I don't know, it caused her to kinda snap or something," her daughter, Bonne McAlpine, told ABC News. "She was very giving, she'd give the shirt off her back. She was that kind of woman. That's why all of this doesn't make sense."

Learn more about Pavlinac, Jesperson, and victims of the "Happy Face Killer" on the latest episode of 20/20, airing Friday, Nov. 5, at 9 p.m. ET on ABC.

If you are experiencing domestic violence, call the National Domestic Violence Hotline at 1-800-799-7233, or go to thehotline.org. All calls are toll-free and confidential. The hotline is available 24/7 in more than 170 languages.

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