In English speaking countries, we use the common law as the basis of our legal system. In its origins, the Norman French occupied England, which was largely unsettled and not at all well policed. So it became relatively easy to have someone charged with a crime, since witnesses were rare. Juries were used to decide guilt and the facts of the case because the Normans did not speak the vernacular very well. Over time, the burden of proof was placed upon the accuser, later the Crown. It has been that way in our system for nearly a eight hundred years. en.wikipedia.org/wiki/Common_law

The origins of law in France, Italy, Spain and a few other places, they follow what is called "civil law," which also includes criminal law. The historical antecedents of that system are the Code Justinian, en.wikipedia.org/wiki/Corpus_Juris_Civilis church law, en.wikipedia.org/wiki/Canon_law the customary law of the place, and the Code Napoleon, which was a re-codification of existing law. en.wikipedia.org/wiki/Napoleonic_code

Under that system, it is the duty of the state to investigate crimes and to only bring charges if there is sufficient evidence to justify them. If accused, the defendant has the duty to try to show the state where it is was wrong in its investigation. en.wikipedia.org/wiki/Burden_of_proof

The "Napoleonic Code," which continues in France and other countries conquered by France, hold that the accused is guilty until proven innocent (thus, the point of Victor Hugo's Les Miserables). This was a re-working of previous monarchical attitudes toward law enforcement (and as Napoleon was emporer, one isn't surprised.) And this is exactly why the "founding fathers" who wrote our Constitution did it the way the did: to avoid those abuses stemming from that attitude. We have enough wrongfully convicted as it is, which makes it really creepy to realize that even with our errors, we've the best judicial system on the planet.

Innocent until proven guilty - that still stands... but governments are really trying hard to prove that we're guilty of something.

One sided surveillance... particularly true in the UK as it is now illegal to photograph police officers.