Like Waterman, Elena Jasmir Lozada, then 24, advertised sexual services on Craigslist. Like Waterman, Lozada kept in regular touch with family members, who became alarmed when they lost contact with her.
And in a pattern that advocates say has become familiar in cases of missing women who worked as prostitutes, Lozada's family says police were slow to act with urgency. Such cases are often stubbornly difficult to solve because the women live dangerously and often disappear. In Lozada's case, the trail went cold quickly.
In their last phone conversation July 6, Lozada told her mother, Carrie Cronkite, that she was hitching a ride to Boston to relocate. About 10 days later, after she had not heard from her daughter, Cronkite called the Portland Police Department.
The detective she reached "did not seem he was all that concerned because of her history" with prostitution and drugs, Cronkite said. "He was feeling she was someplace doing drugs" and suggested Cronkite check hospitals, shelters and Elena's friends for a few weeks before calling police back. The first official missing persons report was filed Aug. 25.
While Lozada's fate remains unknown, sex workers like her and the four women whose remains were found on Long Island's Gilgo Beach in December are often targets of killers who see them as easy prey, and the cases are among the toughest to solve, say police, advocates and experts.
A Suffolk police spokesman said there is no known connection between Lozada and Long Island, or to the Gilgo Beach case. But the circumstances have brought the two Maine families together. Cronkite has spoken with Waterman's aunt and offered up prayers to the family on a Facebook page she set up for her daughter.
There is no precise national tally of prostitute killings. The Doe Network, a volunteer group that tracks missing people and unidentified bodies, has files for more than 80 such unsolved cases linked to prostitution, said spokesman Todd Matthews. Others are among the thousands of unidentified bodies that end up in morgues.
An FBI analysis of violence along highways and truck stops suggests hundreds of prostitutes were victims of murders and other violence.
Women in the sex trade not only are willing to meet strangers, but they end up going to isolated places with little protection. Commonly drug-addicted and often estranged from family and friends, it's not unlike them to drop out of sight for weeks on end. As a result, their disappearances don't always rise to the top of priority lists for busy police departments.
"Let's face it, there's not much outcry for a missing prostitute as opposed to a missing schoolteacher," Matthews said. "It's not right, but that is reality."
Asked about the first response to the missing person report from Lozada's mother, Portland Police Department Lt. Gary Rogers said, "It wouldn't necessarily be unusual for somebody in that lifestyle to leave for a period of time and not be in contact."
Rogers said, "I can understand the family's dissatisfaction with the investigation. They want answers. They want Elena back."
Tracking down someone in that shadowy world is never easy, he said, because there is no obvious trail to follow for people who wander through life.
"You just don't know where they've gone," Rogers said. "They're just real easy targets to be victimized somehow."
Some killers strike again and again.
"A very large percentage of victims of serial killers are prostitutes," said Steven Egger, a criminology professor at the University of Houston at Clear Lake in Texas, who studies serial murders. "It is an extremely difficult type of investigation because in most instances we are talking about a stranger-on-stranger crime."
Families feel ignored
In the Gilgo Beach case, Waterman's remains were found alongside those of three others. Melissa Barthelemy, Maureen Brainard-Barnes and Amber Lynn Costello also were women in their 20s who advertised online as escorts.
Four prostitutes were also found murdered near Atlantic City in 2006 in a case many believed was the work of a serial killer. The victims, described by friends and family as crack-addicted women working as prostitutes, ages 20 to 42, were found in a drainage ditch behind a stretch of seedy motels in Egg Harbor Township. The slayings are still unsolved.
Whereas in most homicide investigations, detectives focus on possible suspects among the victims' acquaintances and start by checking their alibis, they set out with few clues in prostitute cases, experts say.
Investigators in Lozada's disappearance have little to go on. The Portland police are unsure if there is a link between their missing person and the Gilgo Beach victims.
The lack of movement in investigations of missing and slain prostitutes often leaves their relatives and friends feeling ignored.
Such was the case after Wayne Leng of Vancouver, Canada, noticed his close friend and sometime housemate, Sarah de Vries, had gone missing in 1998. The single mother of two was a heroin-addicted prostitute.
About four years later, two of de Vries' purses and her DNA from used condoms were found 20 miles outside Vancouver at the pig farm of Robert "Willie" Pickton, a convicted serial killer now serving a life sentence for the murder and dismemberment of six women. He was charged with killing at least 32, including de Vries.
"I was absolutely frustrated because the case wasn't taken seriously," said Leng, 61. "They were just drug-addicted women and they [the police] were saying they just went to another place and they are transient and just joined another circuit of prostitutes."
The FBI's National Center for the Analysis of Violent Crime launched in 2004 an initiative dubbed "The Highway Serial Killings," to identify and investigate murders committed along truck routes. The victims in those killings, said Special Agent Ann Todd, "are primarily women who live high-risk, transient lifestyles, often involving drug/alcohol abuse and prostitution."
Since the project was launched, FBI crime analysts have compiled information on 580 victims and 275 suspects in sexual assaults, kidnappings and homicides near highways, rest and truck stops, gas stations and restaurants off travel routes. Those victims included 19 from New York State.
Back home in Maine, Lozada's mother still holds hope that she might be found.
She dreams vividly of her daughter returning home, only to wake up to a bleak reality. "It seems like there's some kind of nut out there who is going after these women," she said.
With Bart Jones and Andrew Strickler