Final answer:
The prosecutor must inform the victim of the progress of the case and the victim's rights in criminal proceedings.
Step-by-step explanation:
The prosecutor in criminal proceedings must inform the victim of the progress of the case and the victim's rights. For example, the prosecutor should provide regular updates to the victim regarding the status of the investigation and the trial. Additionally, the prosecutor should inform the victim of their rights, such as their right to be notified of court dates, the right to be present at the trial, and the right to make a victim impact statement.