Creaky_Old_Cop
member
"Using more force than is reasonable can defeat a self defense case" is the term you're reaching for. Necessary and Proportional Force is reserved to law enforcement in the performance of sworn duties, sworn personnel are charged with the duty to pursue, lay hands on, and take into custody using only that level of force which is reasonable, proportional, or necessary to accomplish that duty safely, and to immediately reduce the level of force as resistance diminishes.Using more force than is necessary can defeat a self defense case.
Civilians (Me included now, thank God, since I retired) are limited to the use of Reasonable Force, or in the nomenclature of some jurisdictions Equal Force to defend ourselves from an attack upon our person or other crimes because there is NO duty to "pursue, lay hands on, and take into custody" and the civilian trying to be some sort of masturbatory hero fantasy Rambo by doing so can create a larger danger to the public at large, and most likely get the wannabe hero killed because they're out of their depth in a mud puddle anyway.
In order to be justified in any use of force under the Reasonable Man Principle, one must be able to articulate why a reasonable man, in the same circumstances, knowing what you knew at the time would act in the same way.