If a witness is sworn in, it falls under the heading of perjury, definitely a federal offense. False statements in a deposition are also subject to prosecution.
A federal judge has many functions. The main and most obvious job of a federal judge is to preside over all court hearing in their respective court. Most times in a criminal case they do not decide...
Threatening a federal judge is a criminal offense under federal law 18 USC ยงยง 875, 876. Threats against state judges are addressed by individual states' criminal statutes, which vary.
Federal offenses are setup by the DOJ ( Department of Justice ). Most federal judges are bound by what is called the "Federal Sentencing Guidelines". These guidelines are not difficult to understand....
There's no one major judge in the federal courts. The judge with the highest office is the Chief Justice of the Supreme Court (John Roberts). The other eight Justices are also extremely "major"....