"In Cold Blood” author (6)
I believe the answer is:
capote
'in cold blood author' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for capote that I've seen before include "Truman perhaps" , "American author" , "Truman --, US author" , "French soft cheese" , "Breakfast at Tiffany's writer" .)