Help in a crime (4)
I believe the answer is:
abet
'help in a crime' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for abet that I've seen before include "Make good" , "Encourage or assist (someone) to commit crime" , "Assist (in wrongdoing)" , "Criminally endorse" , "Assist in some nefarious activity" .)