Shuts up when it's an inside job and the police are around (5)

'shuts up when' is the definition.
I can't tell whether this definition defines the answer.

'an inside job and the police are around' is the wordplay.
'an inside job' becomes 'oops' (I can't justify this - if you can you should give a lot more credence to this answer).
'and' is a charade indicator (letters next to each other).
'the police' becomes 'redcaps' (I have seen 'Military police ' mean 'redcaps' so perhaps 'police' could also mean 'redcaps').
'are around' indicates the central letters.
The middle of 'redcaps' is 'c'.
'oops' after 'c' is 'COOPS'.

'it's' is the link.

Can you help me to learn more?