Wichita ? Authorities are trying to determine whether bone fragments unearthed in a Sedgwick County field could be the remains of a Missouri teenager who disappeared more than four years ago.

FBI agents began digging Tuesday after learning the man suspected in the death of Jennifer Long, 16, Independence, Mo., once lived on the property.

The discovery of bone fragments Thursday halted the search until authorities could learn more about the remains, said Jeff Lanza of the FBI’s Kansas City office. He said a forensic anthropologist would try to determine whether the bone fragments were human.

Long has not been seen since the morning of Jan. 22, 1998. She attended her first two classes at Kansas City’s East High School but left school at 9:30 a.m.

She reportedly was seen getting into a car with Wesley Ira Purkey, a plumber from Leavenworth who confessed to killing her and now awaits trial. Purkey, 50, is serving a 32-year sentence in a Kansas prison for the October 1998 beating death of Mary Ruth Bales, 80, at her home in Kansas City, Kan.

Around 1998, Purkey lived in a trailer on the land now being searched.