Aunt is involved with police for pilfering (10)
I believe the answer is:
peculation
'pilfering' is the definition.
(thesaurus)
'aunt is involved with police' is the wordplay.
'is involved with' indicates anagramming the letters (involved can mean confusing or complex).
'aunt' anagrammed with 'police' makes 'PECULATION'.
'for' acts as a link.
(Other definitions for peculation that I've seen before include "embezzlement" , "Misapplying" .)