Legally, wrong thing charged after previous shakedown (9)
I believe the answer is:
extortion
'shakedown' is the definition.
(I know that shakedown can be written as extortion)
'legally wrong thing charged after previous' is the wordplay.
'legally wrong thing' becomes 'tort' (I am not sure about this - if you are sure you should believe this answer much more).
'charged' becomes 'ion' (I've seen this in other clues).
'after' means one lot of letters go next to another.
'previous' becomes 'ex' (prefix meaning former or onetime).
'tort'+'ion'='tortion'
'tortion' after 'ex' is 'EXTORTION'.
Can you help me to learn more?
(Other definitions for extortion that I've seen before include "The obtaining of money by force or threat" , "Extraction of money with menaces" , "Blackmail" .)