Criminal mentions a cop's reimbursement (12)
I believe the answer is:
compensation
'reimbursement' is the definition.
(thesaurus)
'criminal mentions a cop's' is the wordplay.
'criminal' indicates anagramming the letters.
'mentions'+'a'+'cop'='mentionsacop'
'mentionsacop' anagrammed gives 'COMPENSATION'.
(Other definitions for compensation that I've seen before include "An award in recognition of a loss" , "Adjustment" , "cash for injury" , "Amends" , "damages" .)