Some confess to police in bar (4)
I believe the answer is:
stop
'bar' is the definition.
(bar can mean to stop or prevent)
'some confess to police' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'STOP' is hidden in the letters of 'confess to police'.
'in' acts as a link.
(Other definitions for stop that I've seen before include "as per instruction" , "port of call" , "Withhold payment" , "Post (anag.)" , "Pause - prevent" .)