Digital Evidence: Challenging the Presumption of Reliability

Abstract
There is a general tendency among courts to presume that forensic software reliably yields accurate digital evidence. As a judicial construct, this presumption is unjustified in that it is not tailored to separate accurate results from inaccurate ones. The authors illustrate this unfortunate truth by the presentation of two currently uncorrected weaknesses in popular computer forensic tools, methods, and assumptions. Some percentage of these forensic software errors (and ones like them) will necessarily have negative effects on parties, whether in terms of faulty criminal convictions or improper civil judgments. The authors argue that the collective value of these negative effects among parties is far larger than the costs of research and development required to prevent such negative effects. Under a purely rational economic approach to the law, this dynamic constitutes an inefficiency to be corrected through the proper application of rules. The authors advance two approaches to cure current defects. One is through the proper application of scientific jurisprudence to questions of digital evidence and the other is through some combination of certain broad market and social corrections.