Andres Castillo, Petitioner v. the People of the State of Colorado, Respondent.

Summary

The court held that the trial court improperly instructed the jury on the initial-aggressor exception to self-defense because no evidence showed that Castillo initiated the physical conflict by using or threatening imminent unlawful force. The error was not harmless because the prosecution repeatedly relied on the unsupported instruction during closing argument, substantially influencing the verdict or affecting the fairness of the proceedings. The court therefore reversed and remanded for a new trial without deciding whether the separate provocation-instruction error was harmless. Justice Coats, joined by Justice Boatright, dissented, arguing that the jury should have been allowed to determine whether Castillo was the initial aggressor toward the police.