(a) Deadly force means that force which a reasonable person would consider likely to cause death or serious bodily harm. Its use may be justified only under conditions of extreme necessity, when all lesser means have failed or cannot reasonably be employed. A protective force officer is authorized to use deadly force only when one or more of the following circumstances exists:
(1) Self-Defense. When deadly force reasonably appears to be necessary to protect a protective force officer who reasonably believes himself or herself to be in imminent danger of death or serious bodily harm.
(2) Serious offenses against persons. When deadly force reasonably appears to be necessary to prevent the commission of a serious offense against a person(s) in circumstances presenting an imminent danger of death or serious bodily harm (e.g. sabotage of an occupied facility by explosives).
(3) Nuclear weapons or nuclear explosive devices. When deadly force reasonably appears to be necessary to prevent the theft, sabotage, or unauthorized control of a nuclear weapon or nuclear explosive device.
(4) Special nuclear material. When deadly force reasonably appears to be necessary to prevent the theft, sabotage, or unauthorized control of special nuclear material from an area of a fixed site or from a shipment where Category II or greater quantities are known or reasonably believed to be present.
(5) Apprehension. When deadly force reasonably appears to be necessary to apprehend or prevent the escape of a person reasonably believed to:
(i) have committed an offense of the nature specified in paragraphs (a)(1) through (a)(4)[1] of this section; or
(ii) be escaping by use of a weapon or explosive or who otherwise indicates that he or she poses a significant threat of death or serious bodily harm to the protective force officer or others unless apprehended without delay.
(b) Additional Considerations Involving Firearms. If it becomes necessary to use a firearm, the following precautions shall be observed:
(1) A warning, e.g. an order to halt, shall be given, if feasible, before a shot is fired.
(2) Warning shots shall not be fired.