In In re Tony C. (1978) 21 Cal.3d 888, the 13-year-old defendant admitted he had committed rape by threat of great bodily harm, but that he did not appreciate the wrongfulness of the act. (In re Tony C., supra, 21 Cal.3d at p. 899.) The court took judicial notice of his mother's testimony at a prior hearing that the defendant understood the wrongfulness of his acts to steal, to mean that he also knew it was wrong to engage in conduct which the law denominated as rape. (Id. at p. 900.) The court, however, found the error nonprejudicial, as there was ample evidence that at the time of committing the rape, the defendant had full knowledge of its wrongfulness. The defendant had seized the victim with a knife, thrust it against her neck, and pushed her against the wall. He lay on top of her with the knife to her throat and raped her. He then asked if she was going to call the police, took some of her money from her purse and ran off. (Id. at pp. 900-901.) The facts indicated a clear, "even overwhelming" proof that he knew the wrongfulness of his conduct. (Id. at p. 901.)