The State must prove a criminal case beyond a reasonable doubt. When a jury finds someone not guilty, it is not saying the person is innocent , but that the State did not prove the person guilty beyond a reasonable doubt. Appeals take much less time today than a number of years ago, but they still take time. A time is set for the attorneys to argue their case in front of the Supreme Court. The Justices then write opinions, and discuss back and forth, until a decision is reached.
Some cases take longer than others.
He's argued a number of cases before the Supreme Court, and has a good win-loss record. No trials take place in the Supreme Court. There are no witnesses called, and no jury. The Supreme Court hears appeals from people who are unhappy with what happened in the trial court. The Supreme Court hears about 30 appeals each month.