After the beginning of crime, be quick to punish (7)
I believe the answer is:
chasten
'punish' is the definition.
(chasten could historically mean to punish)
'after the beginning of crime be quick' is the wordplay.
'after' is a charade indicator (letters next to each other).
'the beginning of crime' becomes 'c' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'be quick' becomes 'hasten' (I've seen this before).
'c' put next to 'hasten' is 'CHASTEN'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for chasten that I've seen before include "Subdue - a stench (anag)" , "Suppress" , "Castigate or punish" , "Subdue pride of with a stench" , "Censure severely" .)