A strict liability offence is one where you commit the offence without the need for mens rea – the intention of committing the offence (more here: http://en.wikipedia.org/wiki/Strict_liability).
When an offence is a strict liability offence, you commit it by the simple act of contravening the law, whether you intended to or not. A common use of this provision is for traffic laws such as speeding – you cannot claim that you didn't realise the limit was 30 or that you didn't notice you were doing 40, if you are clocked doing 40 in a 30 zone you are guilty, full stop.
In some cases this is a necessary evil. While in general principle prosecuting someone for an action they did not intend to commit is odious, sometimes it needs to be done, otherwise the law becomes unenforceable. This is, indeed, the reason why strict liability was introduced in the first place.
Many strict liability laws can still recognise the lack of mens rea and may treat the defendant differently if it cannot be proved. For example, see the difference between murder and manslaughter. Both are illegal killings but only one has or can prove mens rea.
A number of offences which have strict liability ought to be either amended to require mens rea, or given specific statutory defences. In particular:
Possession of a firearm – you find a gun in a bin, you take it to your local police, they thank you and then arrest you for illegal possession of a firearm. Don't believe me? See this.
Possession of extreme porn – man finds animal porn on his PC, reports it to the police, gets arrested and charged for possession. Expert witness later proves it was downloaded by a virus.
Man visits prostitute who appears quite willing and happy to be doing what she is doing (as she is entitled to by law – you are aware that prostitution is legal in this country, right?). Later turns out she was trafficked into the country. Man gets arrested and goes to jail.
To name but three examples. There are many more. Now in all these cases you can see that there is room for interpretation. The man with the gun might in fact have bought it from a dealer and regretted his action, handing it in to the police with an excuse. Not likely, but possible. The porn guy might have been browsing BeastPorn.com and then realised what he was doing was illegal, and wanted an excuse. So he called the police rather than take the sensible step of nuking his hard drive. Not likely, but possible. The third guy might have been well aware that his date for the evening was in fact in the hands of Albanian mobsters, and just be looking for a way out of jail. Not likely, but possible.
In all those cases, you could investigate and usefully determine the truth, and hence establish mens rea. Strict liability is there primarily because the lawmaker felt that someone getting off because intent couldn't be proved would be unacceptable. This is almost always a political rather than practical decision. Speeding is strict liability because you either do it or you don't. But in all the above cases and plenty of other strict liability offences, there are additional circumstances which should be taken into account, and hence the strict liabilty provision for those offences ought to be removed. In such cases, better a guilty man go free than that an innocent man be convicted – and here I mean guilty and innocent in terms of intent, not whether or not the offence was strictly committed.
I propose that all laws with strict liabilty provisions be reviewed to see if that provision is in the best interests of society and the individual, with an automatic predisposition that unless this can be proved, the strict liability provision should be abandoned.
Why is this idea important?
Strict liabilty laws regularly cause anomalies such as the incident mentioned where a member of the public handed in a firearm he found and was then prosecuted for posession. This was surely not the intent of the law when it was framed. More recently, the imposition of strict liability on the recent law regarding trafficked women was clearly seen as a political move by a feminist minister who was on record as preferring the absolute prohibition of prostitution but who could not get such a prohibition onto the statue books; by making it a strict liability offence, men would be reluctant to use any prostitute, just in case, thus achieving by the back door what the minister could not achieve through the normal process. That is a clear abuse of the principle.
Fundamentally, a person should be able to tell if an action they are going to take will be illegal or not. A person should be able to report crime to the police without falling guilty of that crime themselves in the reporting. Everyone should have the opportunity to explain themselves before a court, and the opportunity to be found not guilty by reason of that explanation if the court approves. Strict liabilty speaks against all the above, and is open to abuse as we have recently seen.
If the government wishes to be taken at face value on its promise to restore civil liberties and remove bad law, the strict liability provisions in many offences which are otherwise perfectly reasonable pieces of legislation would be a good place to start.