Criminal type's associate (7)
I believe the answer is:
consort
'associate' is the definition.
(thesaurus)
'criminal type's' is the wordplay.
'criminal' becomes 'con' (abbreviation for 'convict').
'type' becomes 'sort' (I've seen this before).
'con'+'sort'='CONSORT'
(Other definitions for consort that I've seen before include "Keep company" , "Marriage partner" , "Companion; ship sailing with another" , "wife, perhaps" , "A monarch's spouse" .)