Ample evidence of debts to support policeman (7)
I believe the answer is:
copious
'ample' is the definition.
('copious' can be a synonym of 'ample')
'evidence of debts to support policeman' is the wordplay.
'evidence of debts' becomes 'ious' (I've seen this in other clues).
'to support' is a charade indicator (letters next to each other) (in a down clue, some letters hold others up).
'policeman' becomes 'cop' (I've seen this before).
'ious' after 'cop' is 'COPIOUS'.
(Other definitions for copious that I've seen before include "Redundant" , "Ample" , "good measure" , "abundance" , "Many" .)