Three different silencers at court during the trial, but defence and jury only knew about one of them, the one supposedly bearing an exhibit reference of SBJ/1 - it later transpires that silencers involved in the investigations had three separate exhibit references, SBJ/1, DB/1 and DRB/1. You do not have to be a brain surgeon to be able to work it out that the other two silencers brought covertly to the court where the trial was taking place, were / are the other two silencers in the equation, SBJ/1 and DB/1...