Courts frown on use of force
Courts recognize the right of persons to protect themselves or others from physical attack, but they frown upon the use of force, even when used for self-defense, since it is clearly a breach of the peace. Anyone who uses force against another person, even for self-defense, must be prepared to justify the necessity for the violence. Allowing one to use force to defend him/herself in a self-defense situation is a privilege that permits one to do something that would otherwise be illegal. In many cases, the need to use force will be obvious from the circumstance of the attack. However, if there are any questions about the use of force, the burden will be on the person using the force to justify its use, especially if there were non-violent alternatives available. In a self-defense situation, a Taekwondo practitioner must be concerned with whether the use of force is reasonable under the circumstance and how much force is legally justifiable.
In 1987, In the case of Martin vs. Ohio, the U.S. Supreme Court ruled that due process did not forbid placing the burden of proving self-defense on the defendant. So in effect, the burden of proof shifts from the prosecution to the defendant in cases of self-defense. It also means that to convict, a jury does not necessarily have to believe that the defendant's behavior was unjustified.