Prior fault and contrived criminal defences: coming to the law with clean hands

The concept of ‘prior fault’ presents a number of significant challenges for the criminal law. The focus of criminal law (offences and defences) is necessarily event specific; we target and assess liability in relation to a snap-shot moment in time or a short series of acts, not as a judgement of prior or more general culpability or character. Therefore, prior fault should be largely an irrelevance at the liability stage. However, remaining faithful to this narrow focus in all circumstances would lead to considerable unfairness, creating an opportunity for defendants to manipulate legal rules to their own advantage. Some of the clearest examples of this arise in so-called contrived defence cases. Let’s take the example of self-defence, a general and complete defence where the defendant’s (D’s) use of force against the victim (V) is both necessary and reasonably proportionate. The standard operation of this defence is largely uncontroversial; people should be empowered to defend themselves from unlawful attack. However, what if D manufactures the circumstances of that ‘attack’ in order to use the law of self-defence to ‘justify’ her pre-planned use of force against V. For example, D wants to kill V. D hands V a knife and then goads V continuously until V (as anticipated) lashes out at D. D shoots and kills V in self-defence. In order to understand and analyse examples such as the one above, we must distinguish two points in time within each potential criminal event. First, and standardly, we must look at the time where the potential criminal offence is committed (T2), asking whether the elements of the potential offence are completed, and if so, whether the elements of a potential defence can be found. In our example above, it is likely that the offence of murder was committed by D, but D would also be able to raise self-defence because of the attack from V. Secondly, we must look at D’s conduct prior to the potential crime (T1), to ask if D has done anything to undermine her future use of a defence at T2. In our example, this could be D’s prior fault in planning, and in manipulating V, in order to create the circumstances of her own defence. It is at this second stage, looking back to T1, that legal rules relating to prior fault must be identified and applied. Issues of prior fault are (potentially) relevant across every criminal defence, and this has given rise to a variety of legal rules designed to prevent the application of contrived defences. However, the legal rules relating to prior fault are often unclear and inconsistent between different defences. Basic questions about what D must have done at T1, what she must have intended, and how this can impact liability at T2, all require investigation. In this article, we provide such an investigation. In Part 1 we explore the application of legal rules relating to prior fault within the current law, exposing areas of inconsistency and incoherence. Part 2 discusses the academic response to this inconsistency, including different models of prior fault that have been recommended in an effort to bring coherence to this area of law. Finally, in Part 3, building upon the academic analysis, we set out our own model of legal rules relating to prior fault; a model that we believe can (and should) be applied across all criminal defences. It is contended that the issue of prior fault can be addressed consistently, and that such rules should form part of any codification project