GARDEN CITY, N.Y. – The four women were prostitutes in their 20s, advertising their services online, living on the margins of society and not likely to be immediately missed. They appeared to share similar middle-class childhoods, but it is the way they lived their adult lives that has authorities chasing a serial killer.
The bodies were found in mid-December, strewn 500 yards apart along a deserted barrier island highway off New York's Long Island. Suffolk County police have classified their deaths as homicides, but no suspects have been publicly identified and officials have refused to reveal how they were killed.
Once investigators determined they were all sex workers, though, it wasn't a leap to say they had a killer in common.
Prostitutes are in many ways the perfect victims for a serial killer — and have been throughout history. Gary Ridgway, the Seattle-area "Green River Killer" of the 1980s and '90s, preyed on prostitutes. So have many other notable serial killers, including Jack the Ripper, who terrorized London in the 1880s.
"The abduction is very easy. It's not like breaking into a house and kidnapping someone," said Louis B. Schlesinger, professor of forensic psychology at the John Jay College of Criminal Justice in New York. "And in many instances, police don't know the person is missing for a very long time afterward."
In Atlantic City, detectives have yet to capture the person responsible for the deaths of four prostitutes found in shallow graves near the beach in 2006. And in Daytona Beach, Fla., police have been investigating the deaths of four women found slain in 2005 and 2006. Those women led "high-risk lifestyles" — they were prostitutes or used drugs, and were likely felled by a serial killer, police said.
The women found dead on Long Island grew up in Maine, Connecticut, North Carolina and upstate New York. One was a promising hairstylist. Two others were described as loving mothers; one called home three times a day to speak to her 4-year-old daughter.
An ex-husband of 27-year-old Amber Lynn Costello, originally of Wilmington, N.C., said their marriage ended when they argued over her heroin use.
"I just don't put up with that," said Michael W. Wilhelm, 41, of Kannapolis, N.C. "I told her to hit the road."
Costello was the most recent victim to be seen alive; police say she was last seen in September living in North Babylon, several miles north of where her body was found.
Relatives knew that 22-year-old Megan Waterman of Scarborough, Maine, was advertising her escort services online, but said she was an adult who made her own choices.
Waterman, mother of the 4-year-old, was last seen at a Hauppauge, N.Y., hotel in June 2010. She had apparently traveled to New York on Memorial Day weekend with Akeem Cruz, a 21-year-old Brooklyn man described as her boyfriend. He is serving 20 months in a Maine prison for drug trafficking.
Maureen Brainard-Barnes, also a mother, was the first of the four women to disappear. She left Norwich, Conn., on July 9, 2007, and headed for New York City, planning to return the following day. A Norwich Police Department missing-persons flier notes there are few details about her disappearance.
"When she stopped calling people, everybody knew something was wrong," said Sarah Marquis of Groton, Conn., who described herself as a close friend.
Melissa Barthelemy grew up in Buffalo, N.Y., and trained as a hair stylist. After moving to New York in 2007, she turned to prostitution. Barthelemey family attorney Steven Cohen said she worked as an escort to supplement her income.
"Nobody goes down to New York City to become a prostitute, an escort," he said. "She did this because she was behind on rent from time to time."
Barthelemy's mother thought she was working as an exotic dancer.
"I had spoke to her a few times and told her I wasn't too happy about it," Lynn Barthelemy said. "But I told her to be careful. She said, 'Mom, I'm never alone, I always have a friend and it's just dancing.'"
Police said all four advertised on Craigslist or other online services. Craigslist, which is largely free, has been under prosecutors' scrutiny for years and last month it said it had removed its "adult services" section from both its domestic and its international sites.
Prostitutes who troll the streets for business are the most vulnerable to violence, but "indoor sex workers," including call girls and so-called Craigslist escorts, also contend with dangers, said Sienna Baskin, co-director of the Sex Workers Project at the Urban Justice Center.
"The sex workers are aware of the risks, and there's a lot of shared knowledge on how to reduce the risks," Baskin said. "It can be anything from using condoms to screening clients, asking for references, and choosing where they work, where they feel safest."
Kirsten Davis, the former "Manhattan madam" who ran for governor in 2010 on a platform that included legalizing prostitution, said that when she ran an escort agency, there was some level of screening for the women's protection.
"We wouldn't send a woman someplace where her safety would be jeopardized; we wouldn't send them to skeevy hotels, for instance," she said.
According to the FBI, serial murder is relatively rare; estimates are they account for less than 1 percent of all murders annually. Still, the four deaths have striking similarities to other recent cases, including two on Long Island.
Joel Rifkin, a former landscaper, admitted to committing 17 killings of women between 1991 and 1993 — the most killings attributed to a serial killer in New York history. Most victims were prostitutes. Rifkin, 52, is expected to spend the rest of his life behind bars.
Robert Shulman was convicted in March 1999 by a Suffolk County jury of first-degree murder in the deaths of three women. The following year he was convicted in Westchester County of murdering two other victims. Some of those killed were believed to be prostitutes. He was 52 when he died in prison in 2006.
Associated Press writer Ben Dobbin in Amherst, N.Y., contributed to this report.