Accessorial liability

Accessorial liability is the doctrinal apparatus by which the criminal law extends liability beyond the principal offender to those who participate in the offence as accessories. The doctrine has been the subject of one of the most significant Supreme Court decisions of the modern era: R v Jogee [2016] UKSC 8 corrected what the court described as a ''wrong turning'' in the law of joint enterprise that had stood since Chan Wing-Siu v R [1985] AC 168.

The modern law has three components. (i) The basic accessorial doctrine — accessories who aid, abet, counsel, or procure an offence are liable as principals (s 8 Accessories and Abettors Act 1861). (ii) The mens rea — the accessory must intend to assist or encourage the principal''s offence and have knowledge of the essential matters constituting that offence. (iii) The post-Jogee position on joint enterprise — foresight that the principal might commit a more serious offence is evidence of intent but is not itself sufficient for accessorial liability.

This week traces the doctrinal architecture from the pre-Jogee position (joint enterprise as a separate doctrine; foresight sufficient for liability) through the Chan Wing-Siu / Powell and English line to the Jogee correction and the post-Jogee case-law. The topic connects to W2 (mens rea), W12 (intoxication and mistake — accessory mens rea), and W14 (inchoate — the boundary between conspiracy and accessorial).

Accessorial liability has been part of English criminal law since the medieval period. The Accessories and Abettors Act 1861 s 8 codified the basic position: those who aid, abet, counsel, or procure indictable offences are liable as principals.

The twentieth century elaborated the doctrine. Johnson v Youden [1950] 1 KB 544 established that the accessory must know the essential matters constituting the principal offence. AG v Able [1984] QB 795 confirmed the principle for procurement: the procurer must intend the principal''s offence to be committed.

The Chan Wing-Siu line developed a separate doctrine of joint enterprise. The Privy Council in 1985 held that where two people embark on a joint enterprise, each is liable for the consequences of the other''s actions if those consequences were foreseen as a possibility. The doctrine was applied widely in joint-enterprise homicide cases, with foresight of GBH or death by the principal sufficient to make the secondary party liable for murder.

The 2016 Supreme Court decision in R v Jogee [2016] UKSC 8 (with the Privy Council decision in Ruddock v R [2016] UKPC 7) corrected this. The court held that Chan Wing-Siu had been a wrong turning: foresight that the principal might commit a more serious offence is evidence of intent but is not itself sufficient. The accessory must intend to assist or encourage the principal''s offence — including the more serious offence if charged with it.

The post-Jogee case-law has worked out the implications. The decision did not retrospectively quash convictions but allowed appeals to be considered on a case-by-case basis. R v Johnson [2016] EWCA Crim 1613 set out the test for substantial-injustice appeals.

(1) The basic accessorial doctrine. Accessories who aid, abet, counsel, or procure an indictable offence are liable as principals (s 8 Accessories and Abettors Act 1861). The four verbs cover different roles: aiding (helping at the scene); abetting (encouraging at the scene); counselling (encouraging before the offence); procuring (causing the offence to be committed by another).

Five graded practice questions in the panel below.

See the Further Reading panel for Ashworth, Smith and Hogan, the post-Jogee academic commentary, and the Court of Appeal substantial-injustice authorities.