Castillo v. People

This case primarily considers the initial aggressor exception to self defense. But also pay attention to the case's discussion of self defense more generally, and particularly the burden of proof.

You will not be responsible for burdens of proof, but they are important to understand. Note that even though self defense is an "affirmative" defense, the defendant must merely prove to the judge some evidence that self defense is possible. If the defendant does so, the judge must read to the jury a self defense instruction, and the jury must find that the prosecution has proved, beyond a reasonable doubt, that the defendant was not acting in self defense. 

This burden allocation is often phrased as the defendant has the burden of production (producing some evidence of self defense) and the prosecution has the burden of persuasion (persuading the jury the defendant did not act in self defense).