Is it a denial of equal protection for the court to compel defendant's testimony?

Finally, the Attorney General argues that even if it was a denial of equal protection for the court to compel defendant's testimony, that error was harmless beyond a reasonable doubt under Chapman v. California (1967) 386 U.S. 18, 24 [87 S.Ct. 824, 17 L.Ed.2d 705]. However, in making that argument, the Attorney General simply asserts there was sufficient evidence to support the judgment, even in the absence of defendant's testimony. That is not the test. In assessing whether an error was harmless beyond a reasonable doubt, "[t]he inquiry . . . is not whether, in a trial that occurred without the error, a guilty verdict would surely have been rendered, but whether the guilty verdict actually rendered in this trial was surely unattributable to the error." (People v Johnwell (2004) 121 Cal.App.4th 1267, 1278, italics added.) Where, as here, the claimed error was allowing the jury to rely on defendant's own testimony as a basis for evaluating his mental state, that standard is almost impossible to meet. Indeed, it would be difficult to conceive of a jury ignoring the defendant's own testimony in reaching such a verdict. We certainly cannot say that occurred here, and thus we reject the claim of harmless error.