Proper treat organised for responsible individual (11)
I believe the answer is:
perpetrator
'responsible individual' is the definition.
(I've seen this before)
'proper treat organised' is the wordplay.
'organised' indicates an anagram.
'proper'+'treat'='propertreat'
'propertreat' is an anagram of 'PERPETRATOR'.
'for' acts as a link.
(Other definitions for perpetrator that I've seen before include "One who commits a bad action" , "One carrying out (crime)" , "One who commits (a bad act)" , "responsible individual" , "One committing (an offence)" .)