They've stolen the goods - look, the store has been ruined (7)
I believe the answer is:
looters
'they've stolen the goods' is the definition.
I can't judge whether this definition defines the answer.
'look the store has been ruined' is the wordplay.
I cannot quite see how this works, but
'look' could be 'lo' ('lo' is an archaic exclamation meaning 'look!') and 'lo' is found within the answer.
an anagram of 'store' is 'oters' which is located in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for looters that I've seen before include "Pillagers, freebooters" , "They steal during riots" , "Plunderers" .)