§ 638 Trial of challenge.

When someone challenges how a jury was picked, the court holds a hearing to sort out whether the process was actually done wrong. At this hearing, the judge, court staff, or other officials involved in picking the jury can be questioned about what happened.

It's not just limited to those officials, though. Anyone else who has relevant information can also testify. Both sides get the chance to bring in witnesses and ask questions to either back up the challenge or show that the jury selection was handled properly. The goal is to get a clear picture of what actually took place, so the judge can decide if the challenge has merit.