New York (CNN) -- Police divers returned to a section of a Long Island, New York, bay on Wednesday in their search for clues in the mysterious deaths of at least eight people.
Scraping the underwater sand with metal detectors and long poles with mesh baskets. investigators say they are looking for any evidence that might shed light on what police describe as a possible serial killer case.
"It could be a piece of jewelry, it could be a piece of apparel, anything of interest," said Suffolk County Marine Deputy Inspector Harold Jantzen.
Divers in wet suits walked through shallow water and swam around private docks in the upscale Oak Beach gated community, where the bodies of four woman were uncovered within a quarter mile stretch of each other in December 2010.
The area is also where 23-year-old Shannan Gilbert -- the missing New Jersey woman whose disappearance prompted the initial search -- was last seen in May, 2010.
Police said Gilbert, like the other four women, was a prostitute who advertised on Internet sites such as Craigslist.
She was first reported missing after attending a private party at a home in the Oak Beach community.
A man who lives a few miles from where the remains were found told CNN that a young woman who matched Gilbert's description and "looked like she was partying all night" came to his door at about 5 a.m. on May 1.
"She was screaming 'Help me, help me!' and said somebody was chasing her," said Oak Beach resident Gustav Coletti.
She then ran away when Coletti called 911, he said.
Gilbert has not been found, but it was her case that led to the grisly discovery of the bodies of four women, at least some of whom were wrapped in burlap and discarded in tangled bushes next to an ocean-side Long Island highway.
At least four other bodies were later found nearby in March and April, though medical examiners have yet to identify them.
Two additional sets of remains -- including a human skull -- were discovered last week in bordering Nassau County, police said.
Meanwhile, an exhaustive aerial and land search that has involved federal agents and drawn national attention is being expanded by the use of the dive teams.
"If something or somebody went into the water in the area near the bulk head or even the shoreline, we want to take a closer look at it," Jantzen told reporters.
He said the same divers who searched this area in January returned Wednesday, and benefited by higher tides that allowed them to swim more easily.
The divers also were able to use metal detectors for the first time, he added.