Big house in local police area (5)
I believe the answer is:
manor
This clue is a double definition.
'big house' is the first definition.
(I've seen this before)
'local police area' is the second definition.
(informal term for a police station's local area)
'in' is the link.
(Other definitions for manor that I've seen before include "Mansion of a wealthy person" , "Big house - police district" , "house on estate" , "patch" , "police area" .)