Fish has also upset a criminal (9)
I believe the answer is:
kidnapper
'a criminal' is the definition.
(I know that criminal can be written as kidnapper)
'fish has also upset' is the wordplay.
'fish' becomes 'kipper' (type of fish).
'has' indicates putting letters inside.
'also' becomes 'and' (both can mean in addition).
'upset' shows that the letters should be reversed in order.
'and' back-to-front is 'dna'.
'kipper' going around 'dna' is 'KIDNAPPER'.
(Other definitions for kidnapper that I've seen before include "One wrongly takes" , "criminal" , "Captive abductor" , "One who seizes" , "one to get child removed?" .)