If you cannot tell the difference, you cannot tell the difference. Unfortunate as it may be, the standard of proof for criminal conviction must be high. There's a reason that various legal systems across the world have converged on such principles as proof beyond reasonable doubt, in dubio pro reo, intime conviction etc. basically stating that the legal burden of proof is on the prosecution to present compelling evidence of crime and that the benefit of doubt must go to the accused. It is considered so fundamental and so important that it has made it into the International Covenant on Civil and Political Rights which a majority of countries in the world (including Denmark) have ratified. There must no doubt have been painful lessons in history which led humanity to eventually adopt such ideas. We must be careful to forget those and inadvertently take steps going back towards that direction.