French policeman wants information on armed criminal (8)
I believe the answer is:
gendarme
'french policeman' is the definition.
(I've seen this before)
'information on armed criminal' is the wordplay.
'information' becomes 'gen' (gen is a kind of information**).
'on' is an insertion indicator.
'criminal' indicates an anagram.
'armed' anagrammed gives 'darme'.
'gen' placed inside 'darme' is 'GENDARME'.
'wants' is the link.
(Other definitions for gendarme that I've seen before include "see in Paris!" , "Soldier on police duty" , "alpine pinnacle" , "French policeman has me in danger" , "Member of the French police" .)