Scene of coppers' beat before start of trouble (8)
I believe the answer is:
prospect
'scene' is the definition.
('prospect' can be a synonym of 'scene')
'coppers' beat before start of trouble' is the wordplay.
'beat' indicates anagramming the letters.
'before' is a charade indicator (letters next to each other).
'start of' suggests taking the first letters.
The first letter of 'trouble' is 't'.
'coppers' anagrammed gives 'prospec'.
'prospec'+'t'='PROSPECT'
'of' is the link.
(Other definitions for prospect that I've seen before include "likelihood of event taking place" , "Possibility of future success" , "Search for gold - view - scene - probability" , "work at mine" , "View - likely future" .)