Crime involving ring found by fellow beside barrier (7)
I believe the answer is:
offence
'crime' is the definition.
(I know that crime can be written as offence)
'ring found by fellow beside barrier' is the wordplay.
'ring' becomes 'O' (letter resembling a ring).
'found by' means one lot of letters go next to another.
'fellow' becomes 'f' (abbreviation - of a society etc.).
'beside' is a charade indicator (letters next to each other) (I've seen this in other clues).
'barrier' becomes 'fence' (fence is a kind of barrier).
'o'+'f'+'fence'='OFFENCE'
'involving' is the link.
(Other definitions for offence that I've seen before include "Attack - crime" , "Displeasure" , "taken by one insulted" , "Hurt; military attack" , "The handler" .)