Legislation

It seems to me these two functions should be split. 
Legislation is about creating laws, which are the legal framework for interactions between people.  That works for things like criminal law, and 'common' law - laws relating to contracts, conditions of work, and a whole host of things like that.   But boiling all that down, laws and the courts that uphold them give a socially acceptable way of arbiting between differing views of what is acceptable, and punishing those who refuse to conform.  Laws in themselves hold no power to stop people from committing an act - only they can do that, or a force on hand to sufficient to prevent an act before it is committed.  All the relevant law does is give society a way of punishing someone for doing something unacceptable.  Of course there is some element of deterrence in that, but only for people who think about the consequences of their actions.  I seriously doubt whether anyone in a blind rage to the point of committing murder actually thinks about the consequences before carrying out the act.  To some extent, it might work on companies, where they have enough knowledge to hide the unlawful parts of their activities, and skirt around other parts of laws to their own benefit.