Copper recording appeal catches right criminal (7)
I believe the answer is:
culprit
'criminal' is the definition.
(I've seen this before)
'copper recording appeal catches right' is the wordplay.
'copper' becomes 'cu' (chemical symbol).
'recording' becomes 'lp' (LP is an example).
'appeal' becomes 'it'.
'catches' means one lot of letters goes inside another.
'right' becomes 'r' (common abbreviation).
'lp'+'it'='lpit'
'lpit' placed around 'r' is 'lprit'.
'cu'+'lprit'='CULPRIT'
(Other definitions for culprit that I've seen before include "Person responsible for wrongdoing" , "The one to blame, guilty party" , "Perpetrator of a wrongdoing" , "Criminal" , "he should have conviction" .)