The pickpocket who's an informer? (5,5)
I believe the answer is:
sneak thief
'the pickpocket' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe there's an association between them I don't understand?
'an informer?' is the wordplay.
I cannot quite understand how this works, but
'an' could be 'i' (Roman numeral for one) and 'i' is found within the answer.
'informer?' could be 'sneak' (sneak is a kind of informer) and 'sneak' is found within the answer.
This explanation may well be incorrect...
'who's' is the link.
Can you help me to learn more?
(Other definitions for sneak thief that I've seen before include "he's got some hot booty!" , "nicker?" , "Person who steals via an open door or window" , "Burglar" , "One acting in appropriate way" .)