Under California state law, a defendant is said to have legally acted in self-defense if he/she: Reasonably believed that he/she was in “imminent danger” of suffering bodily injury Reasonably believed that the immediate use of force was necessary to defend against that reasonable fear of imminent peril Used no more force than was reasonably necessary to defend against that danger If the above are true, the defendant has a valid legal defense, and is not liable for a crime. You can expect the prosecutor to question the legitimacy of said self-defense by making points about any of the following: The presence of imminent danger Whether or not a reasonable belief that a threat existed The idea of “no more force than necessary” Whether there was a duty to retreat What happened with the initial aggressor