February 18, 2012 -- Updated 2354 GMT (0754 HKT) NEW: The remains found Friday are thought to have been in the area for some time NEW: "I saw the top of the cranium sticking out of the brush," dog walker says At this time, we cannot say if the remains are connected to any other cases. The grounds are the Upton Ecological Reserve. On December 17, authorities announced that a body discovered earlier in the week along a remote stretch of Long Island beach was that of Shannan Gilbert, the missing New Jersey woman whose disappearance had led investigators to the 10 sets of human remains and the hunt for a possible serial killer. Gilbert, 24, vanished in May 2010 after visiting a client. The Jersey City resident had advertised for prostitution services on websites such as Craigslist, police said. Her body was uncovered December 13 in the wooded marshes of Suffolk County's Oak Beach. That beach is about 9 miles from where the 10 other sets of human remains were found. Gilbert's mother, Mari Gilbert, said in December that police had botched the investigation into her daughter's death and the apparent killings of the other victims. She threatened to sue the Suffolk County police if the FBI didn't take over the case. Attorney John Ray, who represented Mari Gilbert, said that because Shannan -- a resident of Jersey City, New Jersey -- crossed state lines to visit a client in New York, the investigation should be federal. Suffolk County Police Commissioner Richard Dormer "thinks this is some kind of a silly scene for the Suffolk County police to be involved in only because Shannan was an escort," Ray said. Ray accused Dormer's office of violating the civil rights of the victims by inadequately investigating. Mari Gilbert has said she believes that her daughter was murdered by a serial killer. Police, however, maintained that Shannan Gilbert's death was not thought to be the work of a serial killer. Authorities have conflicting theories about whether a serial killer is involved in the other deaths. The remains found Friday are thought to have been in the area for some time. "This has been determined from the vegetation growth in the area around the remains," the police statement said. The age and gender of the remains are to be determined by medical examiners. "I saw the top of the cranium sticking out of the brush," dog owner Matt Samuel said of his discovery. "It looked like it was wrapped in like bed sheets and then put in a plastic bag and duct taped around tight, and I guess over the time the plastic deteriorated ... and the sheets kind of decomposed," he told CNN affiliate News 12 Long Island. In 2000 and 2003, the torsos of two women were discovered in the same area, News 12 reported. Other body parts belonging to the women have been found at Gilgo Beach, and have been linked to the eight other sets of remains found at Gilgo Beach, the affiliate said.