Final answer:
The best phrase to complete the juvenile criminal justice process diagram is 'Intake officer determines whether case should go to court,' highlighting the role of intake officers in the early stages.
Step-by-step explanation:
The juvenile criminal justice process involves several distinctive steps. Unlike the adult system, the juvenile system focuses more on rehabilitation, and one of the first points of contact in the process is often an intake officer. The intake officer plays a critical role early in the process by determining whether the case should proceed in the juvenile court system or be dismissed. Therefore, the phrase that best completes the diagram of this process is 'Intake officer determines whether case should go to court.'