Does a trial court have a sua sponte obligation to give unanimity instruction on the statute of limitations in a conspiracy?

Even were the issue not forfeited, we would not be persuaded the trial court has a sua sponte obligation to give an unanimity instruction on the statute of limitations in a conspiracy. As a general rule, the trial court need only instruct on the statute of limitations when placed at issue by the defense as a factual matter in the trial. (People v. Smith (2002) 98 Cal.App.4th 1182, 11921193, 120 Cal.Rptr.2d 185 (Smith ).) In asserting this general principle does not apply here, Romero relies

[216 Cal.Rptr.3d 838]