Which statement about supplementary reports is correct?

Supplementary reports play a crucial role in the ongoing documentation of investigations. The correct statement highlights that these reports can clarify new developments in an ongoing case. As investigations progress, new evidence may emerge or additional interviews may reveal pertinent information. Supplementary reports allow officers to document these advancements, ensuring that the case file remains complete and accurate. This continuous updating is vital for the integrity of the investigation and can provide insights that are instrumental in moving towards resolution or prosecution.

In contrast, the other statements fail to recognize the fundamental purpose and importance of supplementary reports within the investigative process. They serve an essential function rather than being optional, do generally follow a formal structure to maintain consistency and clarity, and are necessary for all types of cases, not just major crimes. Therefore, the correct understanding of supplementary reports is that they are integral to capturing and communicating updated information pertinent to cases being investigated.