Jessica’s daughter said the Somerton Man investigation was subject to an authority higher than the police.

We could be looking for an individual with a connection to the Salisbury Weapons Development Complex, the South Australian Government, the Australian Federal Government and the nuclear weapon research developed with the assistance of Hitler’s rocket technicians and scientists in both America and Australia.
An individual with a comprehensive knowledge explosive materials and one vetted by the security services of both Britain and the USA. A man with a proven link to America’s Manhattan Project. And finally, someone who not only played a prominent part in the findings of the inquest into the death of the Somerton Man despite not providing any evidence – witnessed a finding that implicated Jessica Harkness in what some think was his murder.
How hard could that be?