Inspector overshadowed in case (half redacted, unfortunately) (8)
I believe the answer is:
lestrade
'inspector overshadowed' is the definition.
(inspector overshadowed by Sherlock Holmes)
'in case half redacted unfortunately' is the wordplay.
'in case' becomes 'lest' (I've seen this before).
'half' means to take half the letters.
'unfortunately' indicates an anagram (a bad or unfortunate spelling).
'redacted' with half the letters taken is 'reda'.
'reda' anagrammed gives 'rade'.
'lest'+'rade'='LESTRADE'
(Other definitions for lestrade that I've seen before include "Old policeman" , "Inspector" , "Detective associated with Holmes" .)