Foolishness, a crime in country Capone abandoned (9)
I believe the answer is:
asininity
'foolishness' is the definition.
(I've seen this before)
'a crime in country capone abandoned' is the wordplay.
I cannot really understand how this works, but
'a' is within the answer.
'crime' could be 'sin' and 'sin' is found within the answer.
'in' is within the answer.
This explanation may well be incorrect...
(Other definitions for asininity that I've seen before include "Stupidity" , "Extreme foolishness" , "Foolishness as of donkey" , "Idiocy" .)