Numerous cases, criminal and civil ones, are observed by a judge without a jury. The judge is who decide which witness is telling the truth, and is who applies the law to decide whether a civil case has been established or in criminal cases, whether there's proof beyond reasonable doubt, that the suspect is guilty (Courts). The United States legal system is founded upon the belief that independent, neutral, and competent judiciary, comprised of men and women of integrity, will understand and apply the law that rules our society. Therefore, the judges plays a big role in preserving the principles of justice and the rule of law and most respect the judicial office and attempt to maintain confidence in the legal system. A judge must at all times avoid impropriety and appearance of impropriety (Courts). .
Judges discretion refers to the power that judges have to interpret some laws. State and federal judges can use judicial discretion, however it's important to emphasize that their discretion is not unlimited. Judges can use their discretion to interpret the laws that already exist, as long as the interpretation does not oppose with the language of the existing law. Judicial discretion is also constrained by the rights assigned in the other branches of the government, and by the doctrine of "stare decisis", or better describe as maintaining what has been decided (Manaugh). In other words Judges does not have the unlimited right to make and interpret laws. If the state or the federal administration passes a law, then it's called statutory law, which judges are compelled to follow, although when the law it's not clear they can interpret it. However they can interpret a law, judges cannot use their discretion to overruled statutory laws. With that been said, if a judge has already made a decision of a matter, all upcoming judges must apply it in their cases. .
Despite the value of ethical behavior, there is a slight guidance in most of the jurisdictions about what is suitable behavior.