When may a firearm be used by a private officer?

A private officer may use a firearm specifically while engaged in their duties, which includes being in uniform. The justification for this is based on the role of private security personnel, who are expected to uphold the law and protect property only while they are actively working. This means that their authorization to carry and potentially use a firearm is linked to their professional responsibilities and not for personal reasons or perceptions of threat when they are off-duty or not in uniform.

In the context of the other choices, self-defense situations or feelings of threat generally apply to a broader context and are not singularly defined by the professional capacity of a private officer. Additionally, the obligation to act within the bounds of their role restricts the use of a firearm to circumstances where they are on duty and properly equipped, which includes being in uniform. Thus, the use of a firearm is strictly regulated and should align with their official duties rather than personal discretion outside of that framework.