The young lady's name is Amy Billig, not Amy Billings. If you're looking for more information about her, her mother wrote a very interesting book titled:Without A Trace: The Dissappearance of Amy Billig--A Mother's Search For Justice, by Susan Billig with Greg Aunapu.
To summarize, Amy dissappeared during the time that two bicycle gangs, the Pagans and the Outlaws, were passing through her town of Coconut Grove, FL. She was known to hitchhike in her hometown, and it seems possible that she could have been picked up (or taken against her will) by one of the bikers. Amy's mother recieved calls from numerous bikers and "biker babes" claiming that Amy had been drugged and kidnapped and was traveling with one of the biker gangs. Each time she traveled to the location of a supposed sighting, her daughter had supposedly already been moved. At one point, long brown hairs were found in a hairbrush that was left at an abandoned biker den; professional analysis showed that it was "consistent" with hairs found in Amy's brush from home.
Sue Billig was eventually contacted by a biker named Paul Branch. He claimed that he had once owned Amy and wanted to get her back. What followed was a saga that took Mrs. Billig around the country for several years, following Branch. He would always claim to know her daughter's whereabouts, but as soon as Mrs. Billig reached the town where Amy was supposed to be held, Branch would "flake out" or get into legal troubles and dissappear. Eventually the Billigs lost contact with Branch entirely.
Mrs. Billig spent thousands of dollars and over 15 years of her life traveling around the United States and even England in search of her daughter. The Billigs were also victims of several extortion hoaxes by various individuals.
Finally, in the mid-90s, a private detective found Paul Branch. He was dying of skin cancer. After his death, Mrs. Billig was called by Branch's widow, who claimed that Branch had made a deathbed confession. In front of cameras for some A&E crime show (can't remember which), the widow told Sue that Amy had died of an overdose at a biker party the day after she dissappeared. The bikers had cut her body up and thrown her to the alligators in the Everglades (this was actually a common biker practice at the time). In front of the cameras, Mrs. Billig accepted this as the truth. Later it was suggested that the widow had made up the story for her own financial benefit.
One other final detail was that Mrs. Billig had been recieiving phone calls from 1974-1995 from a caller claiming that he was holding Amy as a sex slave. The caller was finally apprehended by LE in 1995 and identified as Henry Johnson Blair, a US customs worker. Although he was never proved to have any involvement with Amy's dissappearance, Amy did write about a man named Hank (Blair's nickname) in her journal. She mentioned that 'Hank' had asked her to run away to South America with him. Henry Johnson Blair was moved to South America by his job around 1974. LE has not proven any connection between Blair and the Amy Billig dissappearance to date.
Sorry for the long post, but this case is really interesting to me. Does anyone (Richard, perhaps) have any more info on this case other than what is available in the book? Any theories? This is one of the most interesting missing cases that I've ever heard of, and I'm surprised it hasn't received more discussion on the WS boards.
