Accessorial liability

Accessorial liability is the law’s principal technique for attributing a completed offence to a person who did not personally perform every element of that offence. It matters in almost every serious Criminal Law examination because it joins the earlier Durham topics together: actus reus and causation, mens rea, homicide, non-fatal offences, property offences, defences, intoxication, mistake, and the inchoate offences considered in Week 14. It is not an offence in itself. It is a mode of participation. The accessory is convicted of the substantive offence committed by the principal, subject to proof that the accessory assisted or encouraged that offence and possessed the required fault.

The modern law must be read through R v Jogee [2016] UKSC 8. Before Jogee, the doctrine of parasitic accessory liability allowed liability where D foresaw that P might commit a further offence in the course of a joint enterprise. The Supreme Court and Privy Council held that this had taken a wrong turn. Foresight is evidence from which intention may be inferred; it is not itself the mental element. The central question is therefore not merely whether D foresaw what P might do, but whether D intentionally assisted or encouraged P’s crime, including any necessary mental element of P’s offence.

The vocabulary remains old. Section 8 of the Accessories and Abettors Act 1861 refers to those who aid, abet, counsel, or procure. These words are still used, but the analysis is now more coherent if organised around two broad conduct categories: assistance and encouragement. Aid is assistance. Abet and counsel are forms of encouragement. Procure is usually treated as causal procurement: D brings about P’s offence by endeavour. The prosecution need not always prove that the assistance was a but-for cause of the offence; but it must prove participation in a legally relevant sense, not mere moral disapproval or passive presence.

This topic is especially important for Durham Year 2 students because it tests legal method. In first year, Durham front-loads Tort, Contract, UK and EU Constitutional Law, The Individual and the State, and legal method. The technique acquired there is indispensable here. You must separate primary rules from standards of proof, avoid conflating doctrine with evidence, and explain whether the issue is conduct, fault, derivation, withdrawal, or defence. Good answers do not recite Jogee as a slogan. They ask: who is the principal? What offence did P commit? What assistance or encouragement did D intentionally provide? Did D know the essential facts? Was the offence committed within the scope of D’s assistance or encouragement? Has D withdrawn? Does any personal defence apply? The best answers also recognise that complicity is normatively difficult: it punishes contribution to another’s wrongdoing, but it risks over-extension where groups, foresight, or association are treated as substitutes for individual culpability.

The law of complicity begins with common law distinctions between principals in the first degree, principals in the second degree, accessories before the fact, and accessories after the fact. A principal in the first degree personally committed the actus reus. A principal in the second degree was present at the scene, aiding or abetting. An accessory before the fact counselled or procured the offence but was absent. An accessory after the fact assisted the offender after the offence; modern English law treats that as a separate matter, principally through offences such as assisting an offender, not as liability for the original offence.

The procedural importance of these distinctions has largely disappeared. Section 8 of the Accessories and Abettors Act 1861 makes those who aid, abet, counsel, or procure an indictable offence liable to be tried, indicted, and punished as principal offenders. The substantive analytical distinction remains, however, because the prosecution still has to prove why D is responsible for P’s offence. D’s liability is derivative in the sense that it depends upon the commission of a principal offence, but it is personal in the sense that D must have participated with the required culpability.

For much of the twentieth century, the courts used broad language. Presence at the scene could be evidence of encouragement. Supply of equipment could be assistance. Advice could be counselling. Bringing about the offence by deliberate conduct could be procurement. Cases such as National Coal Board v Gamble and Attorney-General’s Reference (No 1 of 1975) gave practical meanings to the statutory verbs. Yet the deeper problem arose in group offending, especially homicide. Where D and P embarked on one crime, and P committed a more serious crime, could D be liable because D foresaw that possibility? The doctrine that emerged was often called joint enterprise, although that phrase has always concealed several different categories.

By the late twentieth century, R v Chan Wing-Siu and R v Powell; R v English had entrenched the view that foresight of the collateral offence might suffice for secondary liability. This became known as parasitic accessory liability. The doctrine was attractive to prosecutors in group violence cases because it avoided the difficulty of proving exactly who struck the fatal blow or precisely what each participant intended. It was also controversial. It risked convicting D of murder where D foresaw that P might intentionally inflict serious injury, but D did not intend to assist or encourage that conduct. The criticism was not merely technical. Murder carries the mandatory life sentence. The expansion of complicity therefore threatened the principle that serious criminal liability should track personal culpability.

Jogee is the pivotal correction. The Supreme Court held that the common law had wrongly equated foresight with intention. It restored intention to assist or encourage as the mental element. But Jogee did not abolish accessorial liability, nor did it make group liability toothless. It preserved the ability to infer intention from foresight, presence, association, weapons, planning, and conduct. It also accepted conditional intention: D may intend to assist P if a contingency arises. The change is analytical rather than merely evidential. Foresight may be powerful evidence, but the tribunal of fact must ultimately be satisfied that D intended to assist or encourage the crime committed.

Historically, therefore, accessorial liability has moved from procedural classification, to expansive group liability, to a post-Jogee insistence on principled fault. Durham students should present that trajectory carefully. It is not enough to say that joint enterprise was abolished. It was not. Joint principals, ordinary secondary liability, and conditional accessorial liability remain. What was rejected was the special rule that foresight of P’s collateral offence was itself sufficient mens rea. The modern task is to apply ordinary complicity principles with particular care in factually messy group cases.

Begin every accessorial liability problem with the completed offence. Secondary liability is parasitic on a principal offence in the limited sense that someone must have committed the external elements of the substantive crime. That person is usually P. D is the alleged accessory. If no substantive offence has been committed, D may instead be liable for an inchoate offence, especially encouraging or assisting crime under the Serious Crime Act 2007, conspiracy, or attempt. This matters because Week 14 inchoate liability punishes risk creation before completion, whereas accessorial liability attributes the completed offence to D.

The first question is whether P committed the offence. In homicide, did P cause V’s death with the mens rea for murder or manslaughter? In robbery, did P steal and use or threaten force immediately before or at the time of doing so in order to steal? In burglary, did P enter as a trespasser with the relevant ulterior intent, or commit the further offence after entry? You cannot analyse D’s liability before identifying P’s liability. In an examination script, state P’s offence shortly but accurately, then turn to D.

The second question is D’s conduct. The statutory language is aid, abet, counsel, or procure. Aid means assistance. It may be physical, logistical, informational, or psychological. Driving P to the scene, providing a weapon, acting as lookout, disabling an alarm, supplying inside information, or luring V to a place may all be aid. Abet means encouragement or instigation, usually at or near the time of the offence. Counsel means encouragement, advice, or urging before the offence. Procure is stronger: D brings about the offence by endeavour. Procurement normally requires a causal connection. In National Coal Board v Gamble, the Divisional Court treated procurement as producing the offence by endeavour; in Attorney-General’s Reference (No 1 of 1975), secretly lacing another’s drink so that he drove over the limit was procurement.

The case law is best understood as a sequence of problems rather than a list of names. National Coal Board v Gamble gives a practical meaning to procurement. The coal board sold fuel to hauliers knowing that lorries would be overloaded. The court treated procurement as bringing about the offence by endeavour, requiring a causal connection between D’s conduct and P’s offence. This is the classic authority for the proposition that procurement is more than passive facilitation.

Attorney-General’s Reference (No 1 of 1975) illustrates procurement in its clearest form. D secretly put alcohol into another person’s drink, causing that person to drive while over the prescribed limit. The principal driver did the external act of driving while intoxicated, but D caused the offence to occur. The case is useful because it separates procurement from encouragement. The driver need not know that he is being encouraged; D’s liability lies in bringing about the prohibited conduct.

R v Clarkson is the leading warning against treating presence as liability. Soldiers entered a room where a rape was taking place and watched. Their convictions were quashed because mere presence, without proof that the principal offenders were encouraged by that presence or that the defendants intended encouragement, was insufficient. Clarkson is often paired with Wilcox v Jeffery, where attendance at an unlawful performance and subsequent favourable reporting supported liability. The contrast shows that presence becomes accessorial only when it is intentional support or encouragement.

R v Calhaem is important for counselling. D hired another to kill V. The killer did kill V but claimed that the killing was caused by panic rather than by D’s instructions. The Court of Appeal held that counselling need not be the substantial cause of the principal offence in the same way that procurement requires causation. If the offence counselled is committed within the scope of the counselling, liability may follow. The decision has been criticised for loosening causal analysis, but it remains a useful illustration of the difference between counselling and procurement.

R v Powell; R v English represents the pre-Jogee high-water mark of parasitic accessory liability. The House of Lords held that a secondary party could be liable for a collateral offence if he foresaw that the principal might commit it in the course of the joint enterprise. English introduced a limitation where the principal used a weapon fundamentally different from that contemplated. The structure was unstable: it made liability turn on foresight rather than intention, and it produced severe results in murder cases.

R v Bryce concerns practical assistance before the offence. D helped the killer by driving him and providing arrangements connected with the murder. The Court of Appeal treated assistance as capable of founding liability even if it was not the immediate cause of the offence. The case is useful in problem questions where D supplies logistical help and then claims that P would have committed the crime anyway. Causation is not always required for aid, but the assistance must be real and intentional.

R v Gnango is difficult but examinable. Two gunmen fired at each other in a public place; one shot killed an innocent passer-by. The Supreme Court upheld Gnango’s conviction for murder on the basis that he participated in an unlawful gunfight and could be liable for the murder committed by the other participant. The reasoning is controversial, especially because a victim of an attempted murder is not ordinarily liable for the attempt against himself. The case is best treated cautiously, as a special and contested application of participation principles in mutual combat.

R v Jogee is the central modern authority. It rejects the equation of foresight with mens rea and restores intention to assist or encourage. It does not require proof that D desired the offence. It does not prevent liability where D had conditional intent. It does require the jury to ask whether D intended to assist or encourage the crime committed. In tutorial essays, Jogee should be presented as a correction of principle, not as a mere change favourable to defendants.

See practice questions section below.

See further reading section below.