Rex Heuermann was sentenced Wednesday to life in prison without parole.
Police in Nassau County said the mother, previously nicknamed "Peaches" by investigators after a tattoo on her body, had been identified as a U.S. army veteran who was 26 at the time of the killing.
Heuermann's defense has argued that the new DNA methodology has never been tested in New York courts.
The case against the accused Gilgo Beach serial killer, Rex Heruermann, is "heading toward the trial phase," Suffolk County District Attorney Ray Tierney said Wednesday after a brief hearing.
The latest victim, identified as 24-year-old Valerie Mack, was a sex worker in the Philadelphia and Atlantic City areas, according to a superseding indictment that was unsealed on Tuesday.
Valerie Mack, 24, had been working as an escort in Philadelphia and was last seen by her family that year in New Jersey.