Use of Force and Defensive Tactics
Legal framework
Use of force by a private guard is governed by the same standards as self-defense and defense of others: force must be necessary, reasonable, and proportional to the threat, and it ends when the threat ends. A guard may use force to defend themselves or a third person from imminent harm, to prevent a forcible felony, and - narrowly - to eject a trespasser, but only the minimum force required. Deadly force is justified only to prevent imminent death or serious bodily harm. The force continuum runs from presence, verbal direction, and soft empty-hand control, to hard empty-hand control, intermediate weapons (baton, OC spray, conducted energy weapon) where authorized and trained, and finally deadly force. Not every guard carries every tool; carry only what your license and post orders authorize.
Defensive concepts
Know situational awareness (Cooper's color code: white, yellow, orange, red), reactionary gap (distance buys time), contact and cover, and disengagement - the best defensive tactic is often to leave and call for help. Understand positioning (never let a subject get between you and the exit), verbal commands (clear, loud, repeated), and post-incident duties (render aid, call 911, notify supervisor, document, preserve evidence).
Traps and rule of thumb
Traps include continuing force after the threat stops, using a weapon not authorized by the license or post, and confusing "I was angry" with "I was in fear." Rule of thumb: the force stops the instant the threat stops - and you must be able to articulate why each step was necessary.