Showed cop's note in pastry case by journalist (9)
I believe the answer is:
displayed
'showed' is the definition.
(displaying is a kind of showing)
'cop's note in pastry case by journalist' is the wordplay.
'cop's' becomes 'DI's' (detective inspector).
'note in pastry case' becomes 'play' (I can't explain this - if you can you should give a lot more credence to this answer).
'by' says to put letters next to each other.
'journalist' becomes 'ed' (short for editor).
'dis'+'play'+'ed'='DISPLAYED'
Can you help me to learn more?
(Other definitions for displayed that I've seen before include "Shown publicly" , "revealed" , "Exhibited" , "show" , "Showed" .)