In what circumstances will a prosecutor's comments to the jury change the burden of proof?

In People v. Bradford, supra, 15 Cal.4th at page 1339, the prosecutor commented to the jury that the defendant "'presented no alibi witnesses'" and, on a different issue, that "'no evidence has been introduced by [the defense] on that issue.'" Our Supreme Court held that these comments did not shift the burden of proof to the defendant.

In People v. Ratliff (1986) 41 Cal.3d 675, 690-691, the defendant argued that the prosecutor's comments on the defendant's failure to produce any evidence, such as alibi testimony, improperly implied that the defendant had a burden of proving his innocence.

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