Four and a half years ago, Kari Ferrell was just another 17-year-old girl hanging out in Salt Lake City’s straight-edge scene. She lived with her dad—her parents were divorced, and her mom had remarried and moved to Arizona—and spent a lot of time on MySpace. That was where she met Casey Hansen, now 24. “She just kind of messaged me out of nowhere, commenting on my profile picture,” Mr. Hansen said. “It was of Santa Claus holding a sign that said, ‘I don’t exist.’” The two started dating.

After trashing Hansen's life, Ferrell moved on to New York where she preyed on young hipsters, who were charmed by her frank sexuality and claims of music-scene contacts. When that failed, she told them she was dying of cancer.

It’s likely that when Kari Ferrell walked into the Vice magazine offices in Williamsburg, Brooklyn, last month to interview for an administrative assistant job, they thought they’d hit the jackpot. Ms. Ferrell—petite, 22 years old, of Korean heritage—had a huge tattoo of a dragon across her chest and a cute pixie haircut. She was talkative, funny, charming, adorable. She had a tattoo on her back that read “I Love Beards.” She told them she’d been working for the New York office of the concert promotion company GoldenVoice, which puts on huge rock festivals like Coachella near Palm Springs, Calif., and that she’d moved to New York from Utah just a few months earlier. They hired her on the spot.

Salt Lake Police Sergeant Fred Ross told the Observer that his department is looking for Ferrell and will fly to New York or Philadelphia or where ever she has landed to retrieve her.