In this paper Peter Bernard Ladkin, Bev Littlewood, Harold Thimbleby and Martyn Thomas CBE consider the condition set out in section 69(1)(b) of the Police and Criminal Evidence Act 1984 (PACE 1984) that reliance on computer evidence should be subject to proof of its correctness, and compare it to the 1997 Law Commission recommendation that a common law presumption be used that a computer operated correctly unless there is explicit evidence to the contrary (LC Presumption). The authors unders...