(CNN) -- The man charged with abducting and killing a 24-year-old Georgia woman who disappeared while on a New Year's Day hike has been named a suspect in three additional deaths, authorities said Friday.
Gary Michael Hilton directed investigators to Meredith Emerson's body, according to officials.
They include those of an elderly couple in North Carolina and a Florida nurse.
Gary Michael Hilton, 61, is charged with kidnapping with intent to harm and malice murder in the January 4 death of Meredith Emerson, who disappeared three days earlier.
Witnesses have told authorities they saw Hilton and Emerson together, letting their dogs play along a hiking trail in Vogel State Park.
Emerson's dog was later found in nearby Forsyth County.
Hilton led authorities to Emerson's body, which was found Monday in the Dawson Forest Wildlife Management Area, about 30 miles from where she went hiking. Follow the case on an interactive map »
An autopsy showed she died from blunt-force trauma to the head and was decapitated after she died. A memorial service was held for Emerson on Friday. Watch a report about the latest developments in the case »
Hilton is also the primary suspect in the death of Cheryl Dunlap, 46, whose body was found December 16 in Apalachicola National Forest, southwest of Tallahassee, Florida.
Investigators know Hilton was in the area at the time Dunlap disappeared -- 15 days earlier -- because he encountered a forestry agent who wrote down his vehicle's tag number and ran it through a police database, authorities said. No wants or warrants were found.
Hilton is also a suspect in the slaying of Irene Bryant and the presumed death of her husband, John, in October, said Transylvania County, North Carolina, Sheriff David Mahoney.
"So many people have called to tell us they saw Hilton in the area around that time," Mahoney said.
The Bryants disappeared after going for a hike in Pisgah National Forest. Irene Bryant's body was found near the couple's car, but John Bryant's body has not been found.
Prosecutors have said Hilton tried to use a credit or ATM card belonging to Emerson at a bank after her disappearance. In the Dunlap case, authorities released surveillance camera photos of a man they said was using Dunlap's ATM card to get cash on December 2, 3 and 4.
Investigators in the Bryant case have a bank video of a man wearing a yellow jacket -- believed to have belonged to John Bryant -- while using the Bryants' ATM card. Witnesses who saw Hilton on the trail with Emerson on the day she disappeared said he was wearing a yellow jacket, authorities have said.
But officials in Florida and North Carolina said there is no rush to charge Hilton, as he is in custody in Georgia. "We'd like to build our evidence, our case," Mahoney said.
Authorities in Florida and North Carolina have said they want to meet with investigators in Georgia after they process forensic evidence in the Emerson case. Mahoney said he hopes the meeting can take place next week.
Charges in the Bryant case could be filed in both federal and state court, as the Pisgah National Forest is federal land, he said.
A judge sealed the autopsy report on Irene Bryant, and Florida authorities have not released any specifics regarding the cause of Dunlap's death or the condition of her body. E-mail to a friend
CNN's Mike Phelan and Kim Segal contributed to this report.