Marino said state police as well as Muncy police were investigating.
Lycoming County Coroner George Gedon said Witt's body was badly decomposed and will undergo further tests, including DNA analysis.
On Saturday afternoon, two hikers strolling through a wooded patch of Bald Eagle Mountain off Sulphur Spring Road discovered the body. Marino said the body had been lying in the woods ``for several weeks.'' It was found nearly 20 miles from the girl's mother's house in Muncy.
The area where the hikers found the body is owned by the Williamsport Water Authority, which allows people who register to hike or ride bikes on trails there. The area had not been searched earlier because it is so far from Muncy.
In Muncy yesterday, Jolene Witt's mother was taken to a local hospital and sedated after hearing the news, the girl's uncle Bruce Longenecker said. He said he wished authorities had searched harder for the girl.
Several members of Joline's family said yesterday they believe the killer was someone the child knew.
To residents of Muncy, a small, tree-lined town with backyards dotted with doll houses, the pall that Witt's death cast was evident.
Mindy Williamson, whose 10-year-old daughter, Melinda, was a friend of Joline's, said she plucked Melinda out of school because she didn't want her hearing the news on the radio.
``She's very devastated,'' Williamson said. ``She doesn't understand why anybody would do this to a little kid.''
Pastor Donald Edwards of St. Andrew Lutheran Church, who has held several meetings in the last six weeks to pray for Joline's safety, said there was ``a sense of disbelief and shock in the community with the finality of this announcement.''
The last time anybody saw Joline, she was in her bed, nestled in her pink nightgown next to her 6-year-old cousin.
Her aunt Christina Longenecker said she checked on the girls before retiring around 2:30 a.m. But when Joline's mother, Linda Longenecker, checked again two hours later, her daughter was gone and the front and back doors of the house were wide open.
By morning, a massive hunt had been launched. An army of more than 600 people, including police, FBI agents, and civilians from as far away as New York combed the area.
Thousands of fliers emblazoned with Joline's face were posted on trees and walls. Helicopters swooped low over the Susquehanna River, looking for a body. Police said they were on the lookout for potential sex offenders living in the area.
In Muncy, a kind of sadness and fear hung in the air. Parents tightly clutched their children's hands when walking down the street.
Last week, Linda Longenecker confronted with a loaded gun her daughter's father, Lindsey Witt, who had primary custody of the girl and her two siblings, police said.
She told police that Lindsey Witt had refused to let her see her children. Lindsey Witt told authorities the children didn't want to visit the house from which their sister had vanished.
Yesterday, Lindsey Witt said he will press authorities to find his daughter's killer or killers.
``I want the person or persons who took Joline's life to know they are cowards,'' he said in a telephone interview. ``I won't rest, Joline won't rest, until her killers are found.''