The following will prove interesting and useful for anyone running games in a modern European setting, e.g., the one tentatively being built via this blog, or the underlying canonical setting of Lamentations of the Flame Princess, etc.
Under the terms of the Constitutio Criminalis Carolina, actions such as murder, manslaughter, robbery, arson, forgery, homosexual relations and witchcraft were henceforth defined as severe crimes. In particular, the Carolina specified that those found guilty of causing harm through witchcraft should be executed with fire, laying the foundation for the mass witch trials between 1580 and 1680. It was also the basis for the use of obtaining confessions by torture.
So what can the player characters expect if they are arrested in post-1532 Central Europe?
First of all, torture! Torture to obtain more proof is only allowed if there is at least a “half-proof” against the defendant to start with, like for instance two eyewitnesses, or one eyewitness and a partial confession.
The kind of questions the interrogators may ask is also restricted by the Carolina. Basically, no leading questions are allowed. For instance, the interrogator may ask what weapon has been used in a case of murder, but not if it was a knife.
Even the confession has to be corroborated. So if you have confessed under torture that you hid the stolen money in place X, the investigators have to recover the money from place X, or else the confession is not valid.
Also the proceedings have now to be public (contrary to earlier law), and innocent victims of justice can sue the officials.
Some excerpts of the Carolina are available in English here.
this blog entry compiled from the wikipedia and this web-site