Excuse criminal no more (7)
I believe the answer is:
condone
'excuse' is the definition.
('condone' can be a synonym of 'excuse')
'criminal no more' is the wordplay.
'criminal' becomes 'con' (abbreviation for 'convict').
'no more' becomes 'done' (both can mean 'empty').
'con'+'done'='CONDONE'
(Other definitions for condone that I've seen before include "Approve, sanction" , "Forgive, sanction" , "Accept (wrong behaviour)" , "'Excuse, overlook (7)'" , "Turn a blind eye" .)