Get in trouble with the police! (3,2)
I believe the answer is:
cop it
'get' is the definition.
I know nothing about this answer so I can't judge whether this works.
'in trouble with the police?' is the wordplay.
'in trouble' becomes 'it' (this could be a standard abbreviation of which I'm unaware).
'with' says to put letters next to each other.
'the police?' becomes 'cop' (cop can mean informally mean a police officer).
'it' after 'cop' is 'COP IT'.
Can you help me to learn more?
(Other definitions for cop it that I've seen before include "Be punished" , "Suffer the consequences!" , ""get in loads of trouble!"" , "Get it in the neck" , "Get into trouble; be killed" .)