Northampton County Coroner Zachary Lysek said the bones were those of William S. Edelman, Jr., a 65-year-old who most recently lived in Catasauqua.
The remains were located just before 4:30 p.m. Monday in a secluded portion of the Appalachian Trail in Moore Township, the coroner said.
Edelman pleaded guilty to fatally shooting two men and wounding another in Monroe County in 1992, according to state court records. Local media outlets of the time dubbed Edelman "the Kunkletown Killer" during his prosecution, archival reports show.
Edelman served his time and was released on parole, but the 65-year-old's family reported him missing on March 24, as Daily Voice reported.
The cause and manner of death will be released pending the results of an autopsy, Lysek said.
Click here to follow Daily Voice Bristol and receive free news updates.