Can a jury be instructed on a lesser included offense of assault with a deadly weapon?

A trial court has a sua sponte duty to instruct on a lesser included offense whenever there is substantial evidence for a jury to conclude that the lesser offense, but not the greater, was committed. (People v. Prince (2007) 40 Cal.4th 1179, 1265.)

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Assuming arguendo the trial court should have instructed the jury on simple assault as a lesser included offense of assault with a deadly weapon, the error was harmless under any standard of review. (See id. at p. 1267 [reasonable probability of a different outcome standard generally applies to erroneous failure to instruct on a lesser included offense]; People v. Rogers (2006) 39 Cal.4th 826, 872 [harmless beyond a reasonable doubt standard may apply when omission of lesser included offense instruction deprived defendant of right to present complete defense].)

The rationale for requiring instruction on lesser included offenses is to avoid forcing the jury into an " 'unwarranted all-or-nothing choice' " which creates the risk the jury will convict on the charged offense even though one of the elements remains in doubt because "'the defendant is plainly guilty of some offense . . . .'" (People v. Hughes (2002) 27 Cal.4th 287, 365.) Here, there was no risk the jury might have convicted defendant of count 1 assault with a deadly weapon even if it had doubts about the deadly weapon use because it was provided no other option for conviction. To the contrary, the jury was provided the options of convicting defendant of count 2 assault by means of force likely to produce great bodily injury or its lesser offense of simple assault. We have no doubt that even without instruction on simple assault as a lesser offense of count 1, if any jurors had discredited the evidence supporting deadly weapon use, the jury would not have reached a guilty verdict on count 1 but would have returned a conviction on count 2 only. (See People v. Lipscomb (1993) 17 Cal.App.4th 564, 571.)

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