Pointed the finger at copper involved in new case leading to detention (7)
I believe the answer is:
accused
'detention' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'pointed the finger at copper involved in new case' is the wordplay.
'pointed the finger' becomes 'd' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'at' is a charade indicator (letters next to each other) (I've seen this in other clues).
'copper' becomes 'cu' (chemical symbol).
'involved in' means one lot of letters goes inside another.
'new' is an anagram indicator.
'case' anagrammed gives 'acse'.
'cu' placed within 'acse' is 'accuse'.
'd' put after 'accuse' is 'ACCUSED'.
'leading to' is the link.
Can you help me to learn more?
(Other definitions for accused that I've seen before include "Levelled a charge against" , "Indicted" , "Charged with an offence" , "He who stands in the dock" , "Incriminated" .)