With over furlong vandalised, it's criminal (8)
I believe the answer is:
wrongful
'criminal' is the definition.
(thesaurus)
'with over furlong vandalised' is the wordplay.
'with' becomes 'w' (abbreviation).
'over' says to put letters next to each other.
'vandalised' indicates an anagram.
'furlong' anagrammed gives 'rongful'.
'w'+'rongful'='WRONGFUL'
'it's' is the link.
(Other definitions for wrongful that I've seen before include "Not just or fair" , "Unjust or illegal" , "Improper" .)