By a jury of your peers, or if the accused waives trial by jury, then by the presiding judge.
Easy cases are adjudicated by lower courts. Harder cases are decided by the higher courts.
They review cases that has been decided in district courts, in appellate courts, they have only a judge taking a decision.
The supreme Court was overwhelmed by cases.
The majority of cases heard in the Federal Circuit are held in the various US District Courts. The few that are appealed go forward to the US Circuit Courts of Appeal.
Federal courts cannot hear cases concerning divorce. Marriage is a contract between the state and a married couple and it can only be decided in state court.
Federal courts have jurisdiction over cases that involve federal law. There are also a few jurisdiction issues that could bring a state law case into federal court.
The custom of following already decided cases is called "stare decisis," which means to stand by things decided. It is a principle in common law legal systems where judges are required to follow precedents set by higher courts when making decisions in similar cases.
Is it ever possible for cases involving the same issue to be decided differently in different costs of a court system
Yes, the states hear far more criminal cases than the federal courts do.
Circuit splits -- where two of the federal Circuit Courts of Appeal have decided the same issue of law in contradictory ways. Most cases involve US Constitutional issues.
Any case, civil or criminal, decided in the lower trial courts which have been appealed. NOTE: Contrary to common misunderstanding, not all cases are accepted by the Appelate Courts for appeal. The cases are reviewed and only certain ones are chosen for actual deliberation.
Both the US Supreme Court and the US District Courts share original jurisdiction over cases involving foreign diplomats; however, Congress has decided to allow the US District Courts to exercise original jurisdiction in this area. The Supreme Court may choose to hear these cases, but does not.