Final answer:
Judges preside over lower federal courts, and the Constitution guarantees the right to a trial by jury in federal criminal cases. This right is critical for a fair judicial process and is underscored in the Bill of Rights to protect against the abuse of judicial power.
Step-by-step explanation:
People who preside over cases in lower federal courts are called judges. During criminal cases, the Constitution guarantees several rights to ensure a fair trial. One of these rights, according to Section 2 Clause 3 of the Constitution and further emphasized in the Bill of Rights, is a trial by jury. This right is so vital that it is preserved explicitly as an assurance against the potential for any single judge to exercise tyrannical power. In criminal cases, it is the jury's role to determine the guilt of the accused, while the judge may determine penalties. Congress has structured the federal judicial system into three tiers: the district court, circuit courts, and the Supreme Court, with the trial typically beginning in the district court. Precise legal procedures are followed to safeguard the rights of the accused, including the right to legal representation, which may take the form of a public defender for those who cannot afford a private attorney, as described in cases like Gideon v. Wainwright.