Ignore police officers on patrol did you say? (9)
I believe the answer is:
disregard
'ignore' is the definition.
(I know that ignore can be written as disregard)
'police officers on patrol did you say?' is the wordplay.
'police officers' becomes 'DIs' (detective inspectors).
'on' becomes 're' ('on' can be mean 'with reference to').
'patrol' becomes 'guard'.
'did you say?' shows a homophone (sound like).
'guard' sounds like 'gard'.
'dis'+'re'+'gard'='DISREGARD'
(Other definitions for disregard that I've seen before include "Push aside" , "Neglect, ignore" , "Overlook - inattention" .)