This is an extract from Malcolm Barber, The Trial of the Templars, (2nd ed, Cambridge, 2006), which I’ve just been reading, on the Inquisition (pp 28-29):
The accused was interrogated by the inquisitor and his assistants and a summary of the proceedings was recorded by a notary. The aim was to establish guilt, either by confession or by the use of testimonial evidence. He was not allowed a defending advocate, even if he could have found one, and witnesses were reluctant to testify on his behalf for fear of guilt by association. Hostile witnesses were allowed to remain anonymous on the grounds that they might otherwise be intimidated, and the accused could only read a précis of their depositions. In contrast to secular proceedings, all kinds of witnesses could be used, even perjurers, criminals and the excommunicate. The accused could only list his enemies in the hope that some names would coincide with the witnesses. It seems, however, that the inquisitors real aim was to obtain a confession, for, without the admission of guilt, a heretic could not be reconciled to the Church. If confession could not be obtained spontaneously, compulsion would be used, firstly by imprisonment under increasingly harsh conditions and ultimately by torture, supposedly of a limited kind which did not involve the effusion of blood or permanent mutilation.
Im very busy at the moment, trying to understand how the Holy Roman Empire worked, so please fill in the contemporary analogies yourself.