Murder results when two idiots put one over the people (13)
I believe the answer is:
assassination
'murder results' is the definition.
'assassination' can be an answer for 'murder' (I've seen this before). I am unsure of the 'results' bit.
'two idiots put one over the people' is the wordplay.
'two idiots' can mean two substitutions for 'idiot'.
'idiot' becomes 'ass' (both can mean a stupid person).
'idiot' becomes 'ass' (both can mean a stupid person).
'put one over' becomes 'i' (I am not sure about this - if you are sure you should believe this answer much more).
'the people' becomes 'nation' (nation is a kind of people).
'ass'+'ass'+'i'+'nation'='ASSASSINATION'
'when' acts as a link.
Can you help me to learn more?
(Other definitions for assassination that I've seen before include "execution" , "Ordered killing" , "Political killing" , "(Eg, political) murder" , "Politically-inspired murder" .)