Attend course for police (4)
I believe the answer is:
beat
'course for police' is the definition.
'beat' can be an answer for 'course' (thesaurus). I am not certain of the 'for police' bit.
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for beat that I've seen before include "Pound - defeat" , "Surpass (a score)" , "Conquer" , "Strike repeatedly" , "worn-out" .)