To establish criminal liability in Law it is necessary to find the actus rea and the means rea of the crime. While the actus rea is purely concerned with the physical carrying out of the crime. There are a number of instances where that is enough and there is statutory legislation to be found which does not even require the consideration of the Mens rea. For example in Bowsher where the defendant drove a car thinking that he had a driving licence while he did not. The court ruled there was no requirement to establish mens rea and he was found guilty. Likewise in Harrow LBC where the defendant believed that he was selling a lottery ticket to some over the age of 16. He was still held to be liable.

Mens rea can become established during the actus rea of the event. In Fagin a motorist drove accidentally on the foot of a policeman. The police Man asked him to reverse the defendant refused. He argued that he had not mens rea for the crime. The courts decided in this matter that he was guilty as the mens rea was established by his failure to remove his car. Thus mens rea can be established in crime during the actually event of the crime.

It is also not necessary to-do any thing particular to establish mens re or actus reas they can meet by coincidence. In the case of miller the defendant was found to be guilty for failing to put out a cigarette in a house by acting reckless he was found to be liable for the burning down of the house.

There are number of cases where a minor crime is committed the defendant believing that a much worse crime has happened and than acted incorrectly. For example in Church it was held that even if the belief is mistaken that he killed the victim by further subsequent events the mens rea applies to the whole crime.

There is a continually debate of whether there should be any strict liability offences. The argument of for are the promotion of carer, deterrent value, easier enforcement and no risk liability. There how ever strong argument that exist contrary to this argument. The court human right s suggests that strict liability is not approbate in offences conferring serious criminal liability. The house lords has also suggested that there should be strict a presumption of no mens rea in all statutory offences.

Defences
Strictly speaking defences is a means by which the defendant is able to avoid criminal liability. There are though four categories to be considered, Lack of capacity, denial of actus rea, denial of mens rea, justification /excuse. Each one has a mens rea element to be considered. For example in lack of capacity one is dealing with insanity and infancy, this is an unpopular are of law as there little coherent logic following through. For example someone suffering from diabetes may plead insanity so long as they can establish that the effect of their medicine was not due to the proper administration. As laid out in Broom and Perkins and Sullivan. All these points do fall under insanity and automatism. Where a person due to a number of reasons may not full control of their mind.
An important point to not here that self induced intoxication will not permit a party to negate mens rea liability. As it is considered that they have voluntary placed themselves in the situation as a result responsible for any actions that occur. For example in Majestic where intoxicated defendant injured a policeman it was held that was guilty as he chosen his state. In Hardy it was held that where the effect was not predictable than the defend dent could negate the mens rea for burning down his house.

In conclusion it is necessary to have strict liability as there are certain offences that require no mens rea as in the promotion of a caring society it holds all of society accountable. There are also instances where the debate of the relevant means rea is highly questionable as in Fagin.