Facing a violent crime charge sometimes come with an affirmative defense. This is a concept that some people might not understand because they think that they have to automatically claim that they didn't do it in order to fight the charges.
One affirmative defense is claiming that what you did was actually done in self defense. In this case, you agree that you committed the crime, such as a homicide, but you are saying that the circumstances didn't leave you any other choice. This can often be hard, but not impossible, to prove.
In a self-defense situation, there are a few things that you should know. First, you have to have had a fear of imminent danger. This means that you have to act right when the danger is present. You can't think that someone is going to kill you so you go home, get a gun and go back to find that person. The situation that was just described is premeditated murder.
An example of self-defense would be if a robber broke into your house and threatened you at gunpoint, so you pulled your pistol out of your dresser and shot the robber. You have to remember that if you are going to claim self-defense, the danger you say made you fear for your life had to have been something that a regular person would have considered life-threatening.
Of course, there are other instances that might lend themselves to self-defense claims, so you must evaluate the circumstances of the case to determine if what you are claiming would be a suitable defense option.
Source: FindLaw, "Self-Defense Overview," accessed June 29, 2017