The four murdered women all advertised their sexual services on the popular online classified site. Megan Waterman, 22, of Maine was the first victim identified last week.
Using DNA, cops have identified the other vicitms as: Maureen Brainard-Barnes, 25, of Norwich, Conn.; Amber Lynn Costello, 27, of North Babylon; and Melissa Barthelemy, 24, of Buffalo.
ACCORDING TO THE NY POST: The killer's last known victim, Costello, went missing from North Babylon only five months ago on Sept. 2. Waterman was last seen at a Hauppauge Holiday Inn on June 6 of last year, Barthelemy went missing from The Bronx on July 12, 2009, and Brainard-Barnes vanished from Manhattan in July 2007.