What is the legal test for a jury to consider whether a defendant is guilty of the lesser included charge of manslaughter under the California Civil Code of Civil Procedure?

Courts have a sua sponte duty to instruct on lesser included offenses when the offense is supported by substantial evidence, which, if accepted, would permit the jury to find the defendant not guilty of the greater offense and guilty of the lesser offense. (People v. Breverman (1998) 19 Cal.4th 142, 148-149.) A trial court need not instruct the jury on a lesser included offense where no evidence supports a finding that the offense was anything less than the crime charged. (People v. Gutierrez (2009) 45 Cal.4th 789, 826.)

Voluntary manslaughter is a lesser included offense of murder when the requisite mental element of malice is negated by a sudden quarrel or heat of passion or by an unreasonable but good faith belief in the necessity of self-defense. (People v. Elmore (2014) 59 Cal.4th 121, 133; see also 192.) Attempted voluntary manslaughter is a lesser included offense of attempted murder. (People v. Thompkins (1987) 195 Cal.App.3d 244, 255-256.)