All four women found dead on a Long Island beach were prostitutes, and all were murdered in a similar manner, investigators said today as they announced the identities of the victims. Suffolk County DA Thomas Spota said, "I think it fits within the known definition of what a serial killer would be," and asked women involved in prostitution to come forward with information, "I find it very hard to believe that people engaged in the same business as them [don't] know something."

Last week police identified one of the women—Megan Waterman, 22, a woman from Maine who'd been reportedly working as a prostitute—and today the other three are named: Melissa Barthelemy, 24, of the Bronx; Amber Lynn Costello, 27, of North Babylon, L.I.; and Maureen Brainerd-Barnes, 25, of Norwich, Conn.

Barthelemy's mother Lynn had told a Buffalo TV station that her daughter moved to NYC five years ago, winding up as a stripper. She'd been missing since July 2009. "She's a feisty little thing. She loved that fast life," Barthelemy said after her daughter went missing, according to the Daily News. "Before we hung up I always said, 'I love you be careful. If you get in trouble, it's not like you're right around the block. It's going to take me seven hours to get to you.'"

Brainerd-Barnes has been missing since July 2007, and Costello disappeared on Sept. 2nd, 2010. Investigators theorize that the women were killed elsewhere and then dumped at Gilgo Beach. They all advertised on Craigslist, and one source tells the News, "There are substantial similarities in terms of the causes of death."