Police said all four victims had advertised on Craigslist and other online services, The New York Times reported.
"Certainly, it has all the hallmarks of a serial killer," Suffolk County Police Commissioner Richard Dormer told the Times. "Because of the four bodies all found in the same location, they were all connected through the Internet, and the escort, prostitution thing."
The slain women were identified as Maureen Brainard-Barnes, 25, of Norwich, Conn.; Melissa Barthelemy, 24, who had been living in the Bronx but was originally from the Buffalo, N.Y., area; Amber Lynn Costello, 27, who was last seen in North Babylon on Long Island; and Megan Waterman, 22, of Scarborough, Maine.
Brainard-Barnes had been missing since July 9, 2007; Barthelemy since July 12, 2009; Waterman since last spring and Costello was last seen Sept. 10.
Dormer said no arrests had been made and wouldn't say whether investigators had specific suspects they were pursuing.
"That's part of the investigation," he said. "We have made significant progress, and we do have leads."