Unbelievers present at robberies (8)
I believe the answer is:
atheists
'unbelievers' is the definition.
(atheist is a kind of unbeliever)
'at robberies' is the wordplay.
'robberies' becomes 'heists' (heist is a kind of robbery).
'at'+'heists'='ATHEISTS'
'present' acts as a link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for atheists that I've seen before include "ungodly crew" , "Godless people" , "People who believe there is no god" , "They don't believe in a deity" , "They deny the existence of gods" .)