To deal with heartless crime, we have the police (5)
I believe the answer is:
force
'police' is the definition.
(the force can refer to the police force)
'to deal with heartless' is the wordplay.
'to' becomes 'for'.
'deal with' becomes 'cope' (I've seen this in another clue).
'heartless' suggests removing the centre.
'cope' with its centre removed is 'ce'.
'for'+'ce'='FORCE'
'crime we have the' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for force that I've seen before include "Muscle" , "Urge" , "fall" , "Compulsion - police" , "Vehemence" .)