Fascinating how setter distorted crimes (8)
I believe the answer is:
mesmeric
'fascinating' is the definition.
(I've seen this before)
'setter distorted crimes' is the wordplay.
'setter' becomes 'me' (the setter of the clue).
'distorted' is an anagram indicator.
'crimes' with letters rearranged gives 'smeric'.
'me'+'smeric'='MESMERIC'
'how' acts as a link.
(Other definitions for mesmeric that I've seen before include "Hypnotic and compelling" , "Hypnotic, spellbinding" , "Fascinating" .)