What is the legal test for giving jury instructions on a lesser included crime?

In criminal cases the trial court must instruct on the general principles of law relevant to the issues raised by the evidence. That obligation has been held to include giving instructions on lesser included offenses "when the evidence raises a question as to whether all of the elements of the charged offense were present [citations], but not when there is no evidence that the offense was less than that charged." (People v. Wickersham (1982) 32 Cal.3d 307, 323-324, 185 Cal.Rptr. 436, 650 P.2d 311.) In People v. Flannel (1979) 25 Cal.3d 668, 684-685, 160 Cal.Rptr. 84, 603 P.2d 1, footnote 12, earlier cases requiring jury instructions to be given when any evidence is presented, no matter how weak, were disapproved, and a new rule adopted requiring a trial court to instruct on necessarily included offenses only if the accused proffers evidence sufficient to "deserve consideration by the jury, i.e., 'evidence from which a jury composed of reasonable men could have concluded' " that the particular facts underlying the instruction did exist. (People v. Flannel, supra, at p. 684, 160 Cal.Rptr. 84, 603 P.2d 1, quoting from People v. Carr (1972) 8 Cal.3d 287, 294, 502 P.2d 513.) Once there is sufficient evidence to warrant this conclusion, the trial court is obligated to instruct on the theory.