Reasonable means your actions were not negligent, and in accordance with what society expects you to do to protect your own and others interests. You act sensibly, exercising proper precautions, intelligence, and judgment. Just because you reasonably fear serious bodily injury or death, by itself does not justify the use of deadly force. The threat must also be imminent, and you must actually believe the use of force is necessary.
Necessary refers to your actions being required to stop the progression of the use of unlawful deadly force to prevent serious injury or death. Any force used beyond stopping the progression is considered excessive. Never act out of revenge.
Imminent means immediate or about to happen any moment.
Serious Bodily Injury means life threatening, or causing permanent disfigurement or disability.
Deadly Force means force that could cause serious bodily injury or death, like shooting a gun at someone.
Perception and Reaction Time - the time it takes for your brain to recognize and accept that a threat is imminent, and then to react or respond by defending yourself. In auto accidents, this is commonly accepted to be 1.5 seconds. In accessing a concealed weapon, it can be considerably longer. Police officers generally accept that an average perpetrator can go from a dead stop and cover 21 feet in 1.5 seconds. Many concealed carry instructors consider the "danger zone" to be more like 30-feet.
Criminal vs. Civil Liability - punishing a wrongdoer for committing a crime vs. adequately compensating a victim for a wrongful act, including past & future medical expenses, past & future lost earning capacity, loss of enjoyment of life, pain & suffering, and costs of attendant care for severely disabled persons.
