Downfall of criminal later put in court (8)
I believe the answer is:
waterloo
'downfall' is the definition.
(I have seen 'Downfall of Napoleon' mean 'waterloo' so perhaps 'downfall' could also mean 'waterloo')
'criminal later put in court' is the wordplay.
'criminal' indicates anagramming the letters.
'put in' means one lot of letters goes inside another.
'court' becomes 'woo' (both can mean to romance someone).
'later' anagrammed gives 'aterl'.
'aterl' inserted within 'woo' is 'WATERLOO'.
'of' acts as a link.
(Other definitions for waterloo that I've seen before include "Final crushing defeat" , "Belgian battle site" , "Ultimate defeat - London station" , "Where Napoleon Bonaparte lost it" , "The last battle" .)