na-adjective, noun which may take the genitive case particle 'no', noun
unknown; unidentified; unspecified
Used in formal or written contexts to indicate that details such as a person's identity, origin, or date are not known or not given. Often appears in reports, news articles, and official documents.
The identity of the perpetrator remains unknown.
The date is listed as unknown on this document.
An unidentified body was found.
This is an old painting of unknown authorship.
The details of the cause of the accident are unknown.
判明 means that facts have become clear or been confirmed, the opposite of 不詳's sense that details remain unknown.
unidentified; name unknown
Compound of 不 (not) and 詳 (detailed, clear). The meaning 'unknown' derives from the idea of something not being clearly detailed or specified.