Long Island, NY (ABC-WKBW-TV)
Numerous people with possible links to the four slain women who have been identified have come to the attention of police since the investigation began, the officials said.
Police are also looking at people who have had regular or routine access to the beach where the bodies were found, and Investigators are also exploring possible links to the serial killer who murdered prostitutes in New Jersey, they said.
According to one investigator familiar with the case and the behavior of serial killers, this appears to be an organized serial killer who plans methodically and is probably above average intelligence. It appears that the killer usually lures people, then kills them in one place and disposes of the body in another.
This sort of killer is often social -- not a loner -- with family, friends and what would appear to be a normal life, the investigator said.
It was the disappearance of a prostitute that led New York police to stumble on the serial killer's ocean-front dumping ground in western Suffolk County.
Shannan Gilbert, 24, disappeared in May 2010 after arranging online to meet a client. Her disappearance triggered a search in the scrub brush along Gilgo Beach, a popular summer getaway spot, but much less frequently visited in the winter.
In December police found four skeletal bodies, all of them women and all of them prostitutes, but none were Gilbert.
Last week, cops found another four bodies. Those bodies have not been identified, but Suffolk County Police said Tuesday that none of the remains belonged to Gilbert.
Cops obtained DNA samples of Gilbert's family last year and were able to quickly check the remains against those samples.
The police conclusion suggests that Gilbert is possibly a ninth victim of a serial killer.
Cops searched the brush along Gilgo Beach and neighboring Oak Beach last week, looking for the bodies of more women potentially killed and dumped in the thick vegetation, while other detectives worked to create a profile of the man who is stalking prostitutes online and killing them.
Suffolk County police have kept a tight lid on many of the investigation's details, commenting publicly only on the search efforts, including the canine units with cadaver sniffing dogs and a dozen police recruits from the academy brought in to help search for bodies.
Experts outside the investigation consulted by ABC News said cops are compiling a vast database of clues and working up a profile of a single serial killer suspected of killing at least eight women, most of them prostitutes, and dumping their bodies on Gilgo Beach over four years.
In December, while searching for Gilbert, police stumbled on the killer's dumping ground, an area that has turned out to be a seven-mile stretch of beach as more bodies were discovered.
The deaths are likely the result of a single killer who knows the area well, said Brad Garrett, an ABC News consultant and former FBI agent who has investigated dozens of high profile cases including the death of Washington intern Chandra Levy and the 2001 anthrax mailings.
"Given the volume of bodies in one location, it tells me the killer is very familiar with this stretch of road. He grew up there, works there, lives there, or has a reason to frequent area. He feels comfortable stopping on that road at least eight times and dragging women to the sea grass line without worrying about being caught," Garrett said.
Though the profile of the Long Island killer is specific to the clues he has left behind, experts say there are typical traits many killers tend to have.
On average serial killers are white men between the ages of 20 and 40. They were often abused as children, but rarely have criminal records. They typically do not travel far to commit crimes, preferring instead areas they are familiar with and which they can move about without raising suspicion.
Serial killers are also often underemployed, Garret said, and clues at the beach may help investigators determine his job, an important step in narrowing the circle of suspects.
"Some of the women were wrapped in burlap bags," Garrett said. "It's possible that that those bags came from some aspect of his life. Did they have fertilizer in them? Did they have coffee? What might that mean about his job?"
Garrett, however, said that does not mean investigators should immediately assume the killer is a "blue collar transient type."
Instead it's feasible that the killer "leads a normal life," he said. He "could be married and functions well in society. But he has this other dark side to his personality."
Gilbert, like the other identified women, was a prostitute. She disappeared on May 1, 2010 after arraigning to meet a client through Craigslist. An Oak Beach, N.Y., resident told authorities that a woman he believes was Gilbert came to his home at 4:45 a.m. that morning. She fled when he tried to call police.
Serial killers often target prostitutes, said Jack Levin, a criminology professor at Northeastern University who studies serial killers.
"The most common victims are prostitutes. They're easy prey. They get right in the car with a killer. Families are slow to file missing person reports and there is little pressure on police to solve the case because it's a criminal killing a criminal," he said.
Police would not confirm the genders, ages or identities of the newly discovered bodies. They would not comment on the level of decomposition or whether these bodies, like the others, were wrapped in burlap.