What the law actually looks at
In New York, assault is defined by results and states of mind rather than by the act alone. The offense generally requires a physical injury, and the level depends largely on how serious the injury was and on the person's state of mind. Contact that causes no injury is often charged as harassment, a lower-level offense, instead of assault. Other states define assault differently, and some include threats or attempts that cause fear without any contact. That is why two incidents that look alike from the outside can be charged very far apart. The first charge also reflects only what the arresting officer knew that night.
Justification and the question of who started it
Self-defense, which New York calls justification, can apply when a person reasonably believed force was needed to protect against the imminent use of unlawful force. Deadly physical force is held to a tighter standard, and outside your own home New York can expect a person to retreat first when that can be done in complete safety. Whether justification fits usually depends on the sequence of events: who moved first, what was said, whether anyone tried to leave. Because that sequence is so important, a few seconds of video can reshape an assault case, and video from bars, stores, and transit is often recorded over quickly.
Starting a defense well
Do not explain your side to the police or to the other person before speaking with a lawyer, and do not post about the incident. Keep photographs of your own injuries, the clothes you wore, and anything showing where you were and with whom. We review the complaint, the medical records the charge relies on, and any statements, and we send preservation requests for video as early as possible. We also ask about work, school, licenses, and immigration status, since an assault conviction can reach each of them in different ways.