It was explained in Ch.2 that to be convicted of an offence, this typically requires proof that D completed the actus reus with the requisite mens rea, in circumstances where there was no valid defence. For the most serious criminal offences, this is usually true. However, there are some offences which lack a mens rea requirement regarding one (or more) of the actus reus elements. These offences impose strict liability.
These offences are often regulatory in nature and, subject to a few isolated exceptions, statutory in origin. For instance, in the first “modern” case of strict liability,2 D (a tobacconist) was held guilty of possessing adulterated tobacco. An excise officer seized D’s tobacco, having found it adulterated with sugar, molasses and other saccharine matter. D was held liable even though he had no grounds for suspecting that the tobacco was adulterated. However, this does not mean the offence requires no mens rea element. It still had to be shown that D intended to sell the tobacco, but no mens rea was required with regard to the adulteration of the tobacco. Similarly, in the much later case of Alphacell v Woodward, the D company was held liable for causing polluted water to enter a river. The fact that D did not know the pollution was taking place and that they mistakenly thought their filtering system was operating effectively was irrelevant.
The majority of strict liability offences exist within schemes of regulation where the emphasis is on the maintenance of standards such as safety. Regulatory schemes that make extensive use of strict liability cover areas such as food, consumer protection, the environment, agriculture, the countryside, construction, and fire. These areas focus on securing compliance with the law, and administrative remedies such as improvement notices are used extensively. However, as a last resort, a criminal prosecution can be brought, often where there are sustained breaches of regulations. While much of the literature and debate in this area has revolved around these “regulatory offences”, it must be emphasised that there are countless other strict liability offences that do not exist within regulatory schemes.