Evil is a very strong word. I don't think the judges entered Salem hell bent on deliberately perpetrating violence or a lie, although they ended up doing so. They were vain and prideful, and unable to admit their own flaws and mistakes, but I don't think we can say that this makes them evil men. They had good intentions, but their logic and duty was trumped by the common hysteria and fear they shared and faced with the people of Salem.
Because they were also Puritans, I believe their intentions to uphold the law AND root out the sin of witchcraft were pure. However, it doesn't take much to figure out they didn't get it right. They took meals with the girls sometimes. They failed to hear all the evidence. They gave too much credence to the words of young girls given to hysterics. They took the word of children over the word of adults with virtually no discernment. And the worst--they refused to reconsider their position once they had some sense that all was not as it seemed to be. That makes them haughty and arrogant as well as wrong. Their motives and intentions were probably good in the beginning; however, it sure didn't take them long to get it all wrong.
The judges in “The Crucible” can be considered evil because of the way that they act and think throughout the course of the play, particularly toward the end. The audience is first introduced to the judges, Danforth and Hathorne, in Act 3 during the trials. They clearly take the side of the lying girls no matter what type of evidence is being presented to them by the accused. Their evil nature at first lies in the fact that they do not look at both sides of the argument. They probably fear the girls as most people in Salem do but take every word that they say as if they are gods while innocent people are being tortured and murdered because of it. In Act 4 we see their true evil. It is clear that by this point in the play the judge realize that the girls might be lying but instead of acting upon this they say that they can not overturn any of their decisions or go back on anything because then it would basically show that they are weak and did not do their jobs from the start. So instead of saving the lives of innocent people, they allow them to die, being pretty sure that the girls have been lying. This is their true evil – allowing innocent people to die to save their own names.
The judges in "The Crucible" are self-righteous, but I don't think that they are evil. They sit in judgement on the whole witchcraft hysteria, they did not create it. They are guilty, however, of self-preservation tactics, when it becomes clear that the court has been guided by the lies of Abigail Williams and the girls, they do nothing to correct the action of the court. Instead they feel compelled to continue with the executions of innocent people to protect their own authority.
The judges are motivated by fear towards the end of the play when they discover that Abigail has run away, they continue to pursue the executions of John Proctor, Rebecca Nurse and Martha Corey. They are afraid that the townspeople will rise up against them once they discover the whole court process has been based on the lies of a disturbed, unstable young woman seeking revenge on her married lover.