Castillo v. People, 2018 CO 62

Castillo fired a shotgun in a crowded Denver parking lot after an unknown assailant shot at his car; he admitted shooting but claimed he acted in self-defense, believing those he fired at were allied with the initial shooter.
Two uniformed officers (Sergeant Lombardi and Officer Simmons) arrived seconds after the first shots; officers fired at Castillo and were subsequently shot at by him; Castillo was wounded and his cousin (who handled the gun later) was killed by police fire.
At trial Castillo raised only self-defense; the court instructed the jury on self-defense and, over defense objection, on two statutory limitations/exceptions: initial aggressor and provocation.
The jury convicted Castillo of two counts of attempted second-degree murder and one count of second-degree assault, acquitted on two first-degree assault charges, and the court sentenced him to consecutive terms totaling 33 years.
The court of appeals affirmed (finding initial aggressor instruction proper on alternative grounds and provocation error harmless); the Colorado Supreme Court granted certiorari.

Issue	People’s Argument	Castillo’s Argument	Held
Whether the trial court properly instructed the jury on the statutory initial-aggressor limitation to self-defense	Some facts (verbal exchange, trunk opened, testimony variance) provided at least minimal evidence to submit initial-aggressor to the jury	No evidence showed Castillo used or threatened imminent unlawful physical force; popping the trunk or cursing were insufficient to make him the initial aggressor	Reversed: no evidence supported the initial-aggressor instruction and giving it was error
Whether giving the provocation instruction (unsupported by evidence) was harmless error	Any error was harmless because provocation evidence was lacking and unlikely to have influenced the verdict	Provocation instruction was unsupported and, coupled with prosecution argument, could mislead jury	Not decided on merits: court ordered new trial based on initial-aggressor error and thus did not reach harmlessness of provocation instruction

People v. Pickering, 276 P.3d 553 (Colo. 2011) (discusses standards for presenting an affirmative-defense instruction)
Beckett v. People, 800 P.2d 74 (Colo. 1990) (self-defense may rest on reasonable belief and apparent necessity)
People v. Jones, 675 P.2d 9 (Colo. 1984) (reference to requirement of evidence showing victim as initial aggressor)
Marquez v. People, 311 P.3d 265 (Colo. 2013) (defines "same incident" as a single unit of experience)
Kaufman v. People, 202 P.3d 542 (Colo. 2009) (recognizes jurors may try to fit facts to an unsupported instruction, producing prejudice)
People v. Garcia, 28 P.3d 340 (Colo. 2001) (instructional error compounded by prosecutorial argument can warrant reversal)