The mystery of who discarded the bodies of four women along a remote New York beach became even murkier when police determined that the missing woman who triggered the search was not among the piles of bones recovered from the area.
Police began finding women's bodies hidden in bushes along the road of Gilgo Beach when they did a search training exercise, picking a spot where prostitute Shannan Gilbert, 24, vanished last May.
"The Suffolk County Medical Examiner's Office has determined through analysis of forensic evidence that none of the human remains found in Gilgo Beach during the past week are that of Shannan Gilbert," police said in a prepared statement. "Suffolk County Police Homicide Squad detectives have notified Gilbert's family. The investigation into the disappearance of Gilbert is still ongoing."
Police are also trying to determine whether a second prostitute, Megan Waterman, who disappeared in the area last June is among the remains, but there are indications that the corpses appear to have been placed in the area before June.
Suffolk County police returned to the beach today to expand their search for possible additional bodies or fresh clues. Police said they found some evidence Thursday, but did not reveal what that evidence would be.
A 10-mile stretch of highway was shut down for a second day to accommodate the beach combing cops and their cadaver dogs.
Suffolk County Police Commissioner Richard Dormer has tried to downplay fears that a serial killer is on the loose.
"I don't want people to think that we have a Jack the Ripper running around Suffolk County with blood dripping from a knife," Dormer said Thursday. "This is an anomaly."
The developments leave the identity of the four women and possible existence of a serial killer unanswered. It also suggests that Gilbert's remains may also be in the area.
Gilbert was last seen running in terror from a Long Island, N.Y., house in May. On Thursday, police swarmed around the home of Joseph Brewer and confiscated an SUV from his property.
Brewer told WABC-TV that he has passed a police lie detector test.
"Truth and time are my only friends. ... I have nothing to say," Brewer told WABC by phone.
While the speculation about Gilbert was a dead end for investigators, police are still examining whether Megan Waterman, a single mother from Maine, may be another of the victims.
"My gut tells me that Megan is no longer with us," Lorraine Ela, Waterman's mother, said. "It's been heartbreaking the past almost 6½ months."
Shannan Gilbert's Disappearance Proves to Be Dead End in Serial Killer Probe
Waterman's mother said her daughter worked as a prostitute and, like Gilbert, was also known to use Craigslist as a means to find her clients. Megan was last seen June 6 at a hotel in Hauppauge, N.Y., a town near Gilgo Beach.
"Me and my family have tried talking to Megan about the dangers of advertising on Craigslist. She didn't listen to us," Waterman said.
Dormer told ABC News that identifying the bodies will be crucial to the investigation.
"Four unidentified bodies at this point, and it's critical to an investigation to identify the victims," Dormer said. "You know, we're waiting for the science to be completed."
The medical examiner tasked with doing the science said that it could take weeks to complete.
"We need to go to forensic ... dentistry ... and the last stop is to do the DNA analysis," Suffolk County Medical Examiner Yvonne Milewski said.
Forensic psychiatrist Michael Welner said that the high level of decomposition will make identifying the cause of death difficult.
"Many investigators of serial killers focus on signatures and approaches that a serial killer may have taken ... a calling card. A calling card is a lot harder to identify with decomposition so advanced," Welner said.
Police also told ABC News that they are looking at a possible connection to the 2006 unsolved murders of four prostitutes 160 miles away in the boardwalk area of Atlantic City in 2006. They were found lying in a drainage ditch.
"We have been in contact with authorities in Suffolk County. ... It would not be fair for us to comment on their investigation," Atlantic County Prosecutor Ted Housel said in a statement to ABC News on Wednesday.
If it does prove to be the work of a serial killer, it wouldn't be Long Island's first.
In 1993, Joel Rifkin was convicted for murdering 17 women. In 1987, Richard Angelo, nicknamed the "angel of death," murdered 25 patients.