pre-noun adjectival
Literary pre-noun adjectival used in the pattern ...とおぼしき to mean 'seeming to be ...' or 'apparently ...'. Often found in written or formal contexts.
See also: 思しい
彼とおぼしき人物が会場に現れた。
A person who appeared to be him showed up at the venue.
犯行現場とおぼしき場所から指紋が検出された。
Fingerprints were detected at the location that seemed to be the crime scene.
思しい is the base adjective meaning 'apparent' or 'seeming', while 思しき is its classical pre-noun form used in modern literary Japanese.
Classical pre-noun form of the adjective 思しい (おぼしい), from the verb 思ふ (おもふ, modern 思う). The form 思しき is fossilized in modern literary usage.