Objective conclusions from the prosecution heard (3)
I believe the answer is:
end
'objective' is the definition.
(I've seen this in another clue)
'conclusions from the prosecution heard' is the wordplay.
'conclusions from' says to take the final letters (the letters which conclude the words).
The final letters of 'the prosecution heard' are 'END'.
(Other definitions for end that I've seen before include "Time to break-up (3,2,4) - See 12" , "Conclusion or goal" , "Game at bowls" , "Aim; stop" , "For Chelsea or Villa, it's a" .)