Criminal admires weapon (7)
I believe the answer is:
sidearm
'weapon' is the definition.
(I've seen this before)
'criminal admires' is the wordplay.
'criminal' is an anagram indicator.
'admires' with letters rearranged gives 'SIDEARM'.
(Other definitions for sidearm that I've seen before include "weapon" , "Piece" , "Officer may carry this" , "One may be fired" .)