Crime of member of the clergy, beheaded (5)
I believe the answer is:
arson
'crime' is the definition.
(crime of illegally starting a fire)
'member of the clergy beheaded' is the wordplay.
'member of the clergy' becomes 'parson' (parson is a type of clergyman).
'beheaded' means to remove the first letter (the head of the word is removed).
'parson' with its initial letter removed is 'ARSON'.
'of' is the link.
(Other definitions for arson that I've seen before include "Malicious burning to destroy property" , "Illegally firing" , "Incendiary act" , "Fire requiring forensic study" , "Act of a pyromaniac" .)