Perpetrator (7)
I believe the answer is:
culprit
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">perpetrator</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that culprit is a type of perpetrator)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for culprit that I've seen before include "Offender or guilty party" , "The one to blame, guilty party" , "The person to blame, the guilty one" , "Wrongdoer" , "Perpetrator of a wrongdoing" .)