Under Penal Code section 1157,*fn1 "[w]henever a defendant is convicted of a crime . . . which is distinguished into degrees," the trier of fact "must find the degree of the crime . . . of which he is guilty. Upon the failure of the [trier of fact] to so determine, the degree of the crime . . . of which the defendant is guilty, shall be deemed to be of the lesser degree." Here, we consider this section's applicability under the following circumstances: (1) the prosecution's only murder theory at trial is that the killing was committed during perpetration of robbery or burglary, which is first degree murder as a matter of law (§ 189); (2) the court properly instructs the jury to return either an acquittal or a conviction of first degree murder; and (3) the jury returns a conviction for murder, but its verdict fails to specify the murder's degree. We conclude that under these circumstances, section 1157 does not apply because the defendant has not been "convicted of a crime . . . which is distinguished into degrees" within the meaning of that section. Thus, the conviction is not "deemed to be of the lesser degree." (§ 1157.) We therefore affirm the Court of Appeal's judgment.
