From the DDP press release:
After just over a week of research, they identified a husband and wife who both had familial connections to Ashland John Doe’s DNA matches. This couple had six children, but the oldest – Peter Adams – seemed to have dropped off the radar in the 1970s.
While records showed that Adams had attended high school in the Chicago suburbs in the early 1970s, there was no evidence of him being alive past 1977. The team presented this lead to the Virginia Office of the Chief Medical Examiner, and investigators then discovered that Adams had gone missing on March 17, 1977 – six days before the unidentified man had died. Further DNA testing facilitated by the Virginia State Police later confirmed that Peter Adams was indeed Ashland John Doe.