Remarkable police work! (9)
I believe the answer is:
arresting
This clue is a double definition.
'remarkable' is the first definition.
(I've seen this before)
'police work' is the second definition.
(I've seen this before)
(Other definitions for arresting that I've seen before include "Lovely" , "Very striking" , "Copper's work" , "spectacular" , "Running in" .)