DETECTIVES BELIEVED A 13-YEAR-OLD GIRL WHO VANISHED FROM HER CALIFORNIA HOME IN 1981 WAS MURDERED - SO IS A WOMAN IN PHOENIX CLAIMING TO BE HER AN IMPOSTER?

"48 Hours" Investigates in "What Ever Happened to Mary Day?"

Saturday, May 2, 10:00 PM

Mary Day was 13 years old in 1981 when she vanished from her family's Seaside, Calif. home. What's shocking is that there is no record of her parents ever reporting her missing. Years later, after her sister got police on the case, they believed she was murdered. But then there was a turn no one saw coming.

Maureen Maher and 48 HOURS investigate the strange case of the missing teenager, the police investigation years later, and a woman in Arizona who claimed to be her, in "What Ever Happened to Mary Day?" to be broadcast Saturday, May 2 (10:00 PM, ET/PT) on the CBS Television Network.

Sherrie Calgaro, who was just 10 at the time that her sister disappeared, was told Day ran away. The family was not allowed to talk about Day, says Calgaro, who was haunted by what happened. When she became an adult, Calgaro reported her sister missing.

"It was a very hard case to deal with ... other than the family ... Nobody knew she was gone," says former Seaside Police Chief Steve Cercone.

"My mother told me that there were a lot of places in California that you could bury a body and they'd never be found," Calgaro says. "I started believing she was murdered."

Police dug into the case and even brought cadaver dogs to the family home. The dogs indicated there were human remains in the backyard, but investigators could only find a little girl's shoe. Police focused on Mary's stepfather as a suspect. Mary's mother told police her daughter was a habitual runaway.

"I've never seen a case like this," says Cercone.

Then, more than 20 years after Mary Day disappeared, a traffic stop in Arizona turned up a new twist and Cercone got a call he wasn't expecting. "He told me, 'Hey captain,' he says, 'are you sitting down,'" Cercone says of the call. "He says, 'Got to let you know that ... they say they found Mary Day.'"

Who was this Mary Day? Was she the one who vanished in 1981?

48 HOURS: "What Ever Happened to Mary Day?" is produced by Chuck Stevenson. Lauren A. White is the field producer. Doug Longhini and Gayane Keshishyan are the development producers. Chelsea Narvaez is the broadcast associate. Michael Baluzy, Karen Brenner and Jon Baskin are the editors. Gail Zimmerman is the senior producer. Nancy Kramer is the executive story editor. Judy Tygard is the executive producer.

Join correspondent Maureen Maher for a live Q&A on 48 HOURS' Facebook page Sunday, May 3 at 1:00 PM, ET to discuss this investigation.

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