OAK BEACH, NY (CBSNewYork) -- The mother of Shannan Gilbert, the New Jersey prostitute whose remains were found in a marshy area along Oak Beach, is asking federal authorities to take over the investigation into her daughter's death.
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A lawyer for the family says he sent a letter to the Justice Department requesting that the FBI take over the investigation into Gilbert's death as well the deaths of 10 other victims believed to be murdered by a serial killer.
Attorney John Ray said he believes Suffolk County police have botched the case.
"The Suffolk County Police Department is grossly derelict in its duty," said Ray. "The commissioner of police is running the investigation like the Pink Panther."
Gilbert's remains were positively identified by the Suffolk County medical examiner on Saturday.
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Suffolk County Police Commissioner Richard Dormer has said detectives believe Gilbert drowned when she was last seen running and screaming for help in Oak Beach back in May of 2010.
It was while searching for Gilbert on Dec. 11, 2010 when police found the first set of human remains along Ocean Parkway.
By April of 2011, police had discovered 10 sets of remains on Gilgo Beach, all found about seven miles apart along Ocean Parkway.
But friends and family members say they don't agree and believe Gilbert was murdered.
"I believe Shannan was murdered and that she is part of the serial killer case," said Gilbert's mother, Mari Gilbert.
She says she plans to sue if the feds don't investigate.
A cause of death has not yet been determined.
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