Writings hacked by alternative lawyer (10)
I believe the answer is:
prosecutor
'lawyer' is the definition.
(prosecutor is a kind of lawyer)
'writings hacked by alternative' is the wordplay.
'writings' becomes 'prose'.
'hacked' becomes 'cut'.
'by' means one lot of letters go next to another.
'alternative' becomes 'or'.
'prose'+'cut'+'or'='PROSECUTOR'
(Other definitions for prosecutor that I've seen before include "Lawyer" , "Court official" , "One making case against defendant" , "originator of suit" , "One who conducts case against defendant" .)