Police trap; goad (5)
I believe the answer is:
I believe this clue is a double definition.
'police trap' is the first definition.
(police operation designed to trap criminals)
'goad' is the second definition.
(I've seen this before)
(Other definitions for sting that I've seen before include "Painful wound - confidence trick" , "Goad" , "(Bee) wound" , "English musician, b. 1951 -- a sudden pain" , "Bee's weapon" .)