Villain's crimes upset social worker (9)
I believe the answer is:
miscreant
'villain's' is the definition.
(thesaurus)
'crimes upset social worker' is the wordplay.
'upset' indicates anagramming the letters.
'social worker' becomes 'ant' (I've seen this before).
'crimes' is an anagram of 'miscre'.
'miscre'+'ant'='MISCREANT'
(Other definitions for miscreant that I've seen before include "Wretch" , "culprit" , "Offender" , "criminal" , "villain" .)