Smart police operation (5)
I believe the answer is:
sting
I believe this is a double definition.
'smart' is the first definition.
(both can mean to burn or hurt)
'police operation' is the second definition.
(sting can mean a police operation)
(Other definitions for sting that I've seen before include "Goad" , "Carefully planned trap - scorpion's weapon" , "piece of deception" , "Pole from Glasgow" , "Con: leader singer of Police" .)