Whodunit roster (8)
I believe the answer is:
suspects
'whodunit roster' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for suspects that I've seen before include "Believes to be guilty but without proof" , "Surmises" , "Believes, supposes" , "Fears" , "Possible criminals - round up the usual ones" .)