'Hoist with his own petard'? Guilty lies and ironic inferences in criminal proof

Abstract

The criminal trial is adversarial. The prosecution necessarily advances a different position to the defendant. The defendant may for example say, 'I was at home with my wife at the time the robbery was committed.' At a minimum, the prosecution will argue that this statement is a lie. The prosecution may go further, claiming that the lie discredits other of the defendant's statements – the 'credibility lie' argument. Or the prosecution may go further still and argue that the lie was told in order to conceal the defendant's guilt. The defendant's 'guilty lie' is proof of their guilt. This article is concerned with the logical limits of the guilty-lie inference.