Gutter criminal -- that's about right (6)
I believe the answer is:
trough
'gutter' is the definition.
(I know that gutter can be written as trough)
'criminal that's about right' is the wordplay.
'criminal' becomes 'tough' (tough can mean a violent person).
'that's about' indicates putting letters inside.
'right' becomes 'r' (common abbreviation).
'tough' going around 'r' is 'TROUGH'.
(Other definitions for trough that I've seen before include "Narrow channel" , "Feed manger" , "Long container for animals' food or drink" , "Container from which cattle or horses feed" , "period when little is achieved" .)