It is clear that the judges, in particular Danforth, and Parris, question the witnesses in Act III in a way that does nothing to help the cause of justice. What is vital to remember is that each of the main judges or the people involved in the case clearly have their own perspective on the witch trials, and their own motives for ensuring that people continue to be accused. Parris, for example, is using this situation to bolster his own authority, whereas Danforth feels he is chosen by God to bring down a massive work of the evil one. These perspectives prevent them from seeing the true situation, and causes them to judge the witnesses before they have even heard the evidence. Note how Danforth presses Mary Warren at the first sign of faltering:
I cannot hear you. What do you say? Mary utters again unintelligibly. You will confess yourself or you will hang! He turns her roughly to face him. Do you know who I am? I say you will hang if you do not open with me!
It is clear that Danforth is not interested in the truth: he has decided his truth, and he will wring that truth from Mary Warren whether she likes it or not. With this kind of pressure placed on the witnesses, it is no wonder that so many confessed to crimes they did not commit and were not guilty of. The whole system of asking the witnesses questions was not aimed at gaining true justice.