Why might a security officer need to know first aid?

A security officer's knowledge of first aid is essential because it enables them to provide immediate assistance in medical emergencies, which can be critical in saving lives or reducing the severity of injuries until professional medical help arrives. In many situations, emergencies can occur unexpectedly, and the quick action of a trained individual can make a significant difference in the outcome for victims. This training emphasizes the importance of being prepared for health crises, emphasizes responsiveness under pressure, and increases the overall safety of the environment the security officer is responsible for.

The other options focus on skills and tasks that, while important, do not directly relate to the immediate care of individuals in medical emergencies. Assisting in investigations, securing facilities, and managing conflicts all pertain to aspects of security management and response but do not address the immediate needs that arise during medical situations. Thus, the primary reason for a security officer to know first aid centers around the need to act quickly and effectively during health-related emergencies.