Yes, if substantial evidence supports a legally recognized mitigation theory. California’s official CALCRIM No. 603 covers attempted voluntary manslaughter based on heat of passion; No. 604 covers imperfect self-defense. Both are lesser options to attempted murder, and both still require intent to kill and a direct but ineffective step toward killing.
Heat of passion: CALCRIM 603
The evidence must support more than anger or an argument. The defendant must actually have acted under intense emotion from provocation, and the provocation must be such that a person of average disposition would act rashly and without due deliberation. The defendant must have been so influenced when acting, without enough time for reason to return. The jury evaluates the circumstances and timing shown by the evidence.
Imperfect self-defense: CALCRIM 604
This theory requires evidence that the defendant actually believed someone was about to kill or cause great bodily injury, and actually believed immediate use of deadly force was necessary. At least one of those beliefs must have been unreasonable. A fear of possible future harm is not enough. The defendant also cannot claim imperfect self-defense if the wrongful-aggressor limitation applies.
A complete and reasonable self-defense claim is different: it may require acquittal, not a manslaughter reduction. If the evidence instead raises a genuine question whether the defendant intended to kill, that is a separate element challenge; California does not recognize attempted involuntary manslaughter as a substitute lesser offense.
Connect the evidence to the instruction
At the instruction conference, identify the attempted-murder count and act, the evidence of intent and direct step, and the specific facts supporting each requested mitigation instruction. For heat of passion, focus on provocation, its objective adequacy, the defendant’s actual emotional state, and cooling time. For imperfect self-defense, identify the perceived immediate threat, the force believed necessary, and any aggressor facts. The prosecution must prove beyond a reasonable doubt that the defendant did not act under a supported form of mitigation.
The court’s instruction decision depends on whether the record contains substantial evidence for the theory; a defendant’s label or argument alone does not guarantee an instruction. Preserve the proposed instruction and ruling. The broader Los Angeles homicide defense page provides related practice information.
The Law Offices of David S. Chesley can review the trial record and instruction issue. Call (800) 755-5174.