Brand student first murder victim (5)
I believe the answer is:
label
'brand' is the definition.
(I know that label is a type of brand)
'student first murder victim' is the wordplay.
'student' becomes 'l' (as in L-plates for learner drivers).
'first murder victim' becomes 'Abel' (Abel was murdered by his brother Cain in the Bible).
'l'+'abel'='LABEL'
(Other definitions for label that I've seen before include "Put a name to" , "Identity tag" , "Identifying tag" , "Tag, tab" , "Means of identifying" .)