Guilty party (7)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">guilty party</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for culprit that I've seen before include "One perpetrating crime" , "The one to blame, guilty party" , "baddie" , "Perpetrator of a wrongdoing" , "Offender or guilty party" .)
(Other definitions for perpetrator that I've seen before include "Committer (of a crime)" , "One who commits a bad action" , "One carrying out (crime)" , "One who commits (a bad act)" , "One committing (an offence)" .)