First off, the legal systems that exist in nation states derived from British heritage are completely different to that of the roman empire. The roman empire had what is known as an inquisitorial...
im from dominican republic but i have no idea...all i know is that.. the law is crazy over there... people pretty much do what ever they want... 95% of the time the police wont mess or do anything...
In the US, we have an adversarial legal system. Basically, this comes down to the fact that there are two (or sometimes more) sides that oppose each other, and the court has the position of listening...