Assault in California is defined under Penal Code section 240 as an “unlawful attempt, coupled with a present ability, to commit a violent injury on the person of another.” (Pen. Code § 240.) To find a person guilty of simple assault, the District Attorney must prove beyond a reasonable doubt that the individual did an act that by its nature would directly and probably result in the application of force to another person, the individual acted willfully, when the individual acted, he or she was aware of facts that would lead a "reasonable person" to realize that his or her act by its nature would directly and probably result in the application of force to some other person, and when the individual acted, he or she had the present ability to apply force to a person. Additionally, the person was not acting in self-defense or in the defense of someone else. (Calcrim 915.)
Someone commits an act “willfully” when he or she does it willingly or on purpose. It is not required that he or she intend to break the law, hurt someone else, or gain any advantage.
The terms “application of force” and “apply force” mean to touch in a harmful or offensive manner. The slightest touching can be enough if it is done in a rude or angry way. Making contact with another person, including through his or her clothing, is enough. (Calcrim 915.)
The touching does not have to cause pain or injury of any kind. In fact, the touching can be done indirectly by causing an object, or someone else, to touch the other person. The District Attorney is not required to prove that the defendant actually touched someone. Nor is the District Attorney required to prove that the defendant actually intended to use force against someone when he or she acted. No one needs to actually have been injured by the individual's act. (Calcrim 915.)