Suffolk County Assistant District Attorney Robert Biancavilla made the revelation after the sentencing of 51-year-old John Bittrolff.
The Manorville man received consecutive 25 years-to-life sentences for the beating deaths of two prostitutes. A jury deliberated for seven days before convicting him in May. Bittrolff denied killing the women and intends to appeal.
Police on Long Island are still investigating the unsolved killings of 10 victims of an apparent serial killer or killers. The 10 bodies were found with a couple of miles of one another, and several of the victims have been identified as prostitutes. Until Tuesday, no suspects had been identified in any of the deaths.
But Biancavilla said after the sentencing that remains of some victims found along Gilgo Beach "may be attributed to the handiwork of Mr. Bittrolff." He said the investigation was ongoing.
A spokesman for the Suffolk County Police Department said detectives do not comment about ongoing investigations.
Bittrolff's attorney, Jonathan Manley, said there was never a mention of any connection between his client and the Gilgo killings throughout the trial.
"This was never mentioned before," Manley said. "This is a serious accusation with absolutely no factual basis. Mr. Bittrolff maintains his innocence in the deaths of Ms. Tangredi and Ms. McNamee and any insinuation that he had anything to do with the Gilgo killings is laughable and meant simply to attract headlines."
Whenever the killer or killers of the victims in the Gilgo case are apprehended, the statements by Biancavilla will "significantly impede the prosecution by immediately creating reasonable doubt," Manley said.
The nude bodies of 31-year-old Rita Tangredi and 20-year-old Colleen McNamee were found 9 miles (14 kilometers) apart in late 1993 and early 1994. Both women had been strangled and suffered severe head injuries. Testimony during the trial revealed the women were drug addicts and prostitutes.
"Bittrolff picked these women because they were vulnerable," the prosecutor said. "He picked them because he thought no one cared about them. But there were people who cared about these girls."
The killings remained unsolved for two decades until Bittrolff's 2014 arrest after homicide detectives linked evidence found on the women's remains to his DNA. The women's bodies were found about 35 miles from the Gilgo Beach site.
The trail that police said led to Bittrolff began with a DNA sample submitted by his brother Timothy Bittrolff following his misdemeanor conviction for violating an order of protection in 2013. State police investigators determined the sample was a partial match to DNA left on the two dead women.
Although his brother was eliminated as a murder suspect, police obtained a DNA sample from John Bittrolff's garbage left outside his Manorville home and later arrested him in the killings. His attorney said during the trial that evidence that Bittrolff had sex with the women was not enough to prove he was the killer.
Biancavilla said this was the first conviction in a homicide case in New York state involving "partial match" DNA.
A K-9 officer and his cadaver dog were on a training mission searching for a missing prostitute in December 2010 when they happened upon what would become, by spring of the following year, 10 sets of human remains - eight women, one man and one toddler.
The remains of an 11th woman, the missing prostitute who sparked the initial search, were found about a year later just miles from where the other 10 were discovered.
The remains were found strewn along several miles of thicket adjacent to Ocean Parkway, east of Jones Beach. Some of the remains found along the parkway were linked to the partial remains of a woman whose body was found in Manorville, about 40 miles (64 kilometers) away.
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