From the right forensics reveals suspected arsonist (4)
I believe the answer is:
nero
'suspected arsonist' is the definition.
(reference to the Great Fire of Rome)
'from the right forensics reveals' is the wordplay.
'from the right' is a reversal indicator.
'reveals' indicates a hidden word.
'oren' is hidden in the letters of 'forensics'.
'oren' back-to-front is 'NERO'.
(Other definitions for nero that I've seen before include "Tyrannical Roman emperor" , "Roman Emperor, 54-68 AD" , "Ruler" , "Emperor, 'burnt' Rome" , "Famous fiddler" .)