Compulsive thief (12)
I believe the answer is:
kleptomaniac
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">compulsive thief</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for kleptomaniac that I've seen before include "Motiveless thief" , "A man to pickle (anag) - one with an urge to steal" , "Compulsive thief" , "Obsessive thief" .)