By week's end, police brass appeared to concede they were stumped, even backing away from earlier notions that a serial killer may be responsible.
"We have no idea whatsoever whether we're dealing with a serial killer," Deputy Inspector William Neubauer told reporters Friday.
"Anything is possible at this point because there's so many unanswered questions."
Early suspicions were that the bodies may have been two escorts who booked clients via Craigslist - one from New Jersey and one from Maine - who disappeared in May and June on Long Island, across Great South Bay from Jones Island, where the remains were found.
Police found the first body Dec. 11 while investigating the disappearance of the New Jersey woman; the other three were found two days later.
Detectives believe the four women probably died elsewhere and were dumped just off the highway, but they remain open to any scenario. Could a lazy funeral director have left them there? Could the bodies have been stolen from a cemetery? Or is it a serial killer after all?
"We're looking at every possibility," Neubauer said.
During the week, a prosecutor in New Jersey contacted Long Island authorities, noting similarities with a 4-year-old case in which four prostitutes' bodies were found in a drainage ditch just outside Atlantic City and about a mile from the beach. Those killings remain unsolved.
On Thursday, detectives had eliminated the Jersey City escort as a possible victim and the following day said it appeared unlikely the other woman was among the dead.
The bodies appear to have been systematically dumped on the remote stretch of highway - about nine miles east of Jones Beach, in a place where the only reason for a driver to stop is a flat tire. The highway from Jones Beach eastward has no streetlights and very few homes, making it an attractive place for a killer to dump prey in the middle of the night.
The bodies were in various states of decomposition; one victim appeared to have been dead for 18 months or longer. Local authorities have sought the expertise of the New York City medical examiner to help determine the women's identities, a task they said could take up to a month.
"There's families out there who have lost loved ones who are wondering if their daughter is one of these four," Suffolk County Police Commissioner Richard Dormer told reporters this week. "So we want to do whatever we can to bring this to a conclusion."
Investigators are also scouring missing-persons reports from the New York area for any leads. The Suffolk County medical examiner said officials eventually hope to submit DNA samples from the victims to a national database of missing people.
An expanded search of more than 15 miles of the highway wrapped up Friday with police declaring it unlikely that other bodies would be found.
The dumping spot is relatively far from even the tiniest of populated communities. The 2000 Census found little more than 300 year-round residents living in three private enclaves several miles from where the bodies were dumped.
While crime victims have frequently been found in remote Long Island locations - several bodies were unearthed in remote eastern sections of the Long Island Expressway and the FBI has recently been looking for victims of mob hits in a Farmingdale industrial park - this is the first time in recent memory that any corpses have been found on the parkway leading to Jones Beach.
"It is unusual to have anything of this nature happen here; it's such a quiet community," said Dorothy Warren, who lives in Oak Beach, about three miles from where the bodies were found. "I am at a loss as to who could have done it.
"I just hope it wasn't one of my neighbors."