In People v. Diaz (1984) 152 Cal.App.3d 926, the defendant was convicted of assault with a deadly weapon ( 245, subd. (a)), a knife, and argued on appeal he was denied an impartial jury because the trial court did not discharge the jury foreperson upon learning she had concealed her history of having been assaulted at knifepoint during an attempted rape. (Diaz, at pp. 929-930, 931.) Specifically, the defendant argued that had he known of this history, he would have exercised one of his three remaining peremptory challenges to excuse the juror. (Id. at pp. 932, 936.) The reviewing court observed: "The denial of the right to reasonably exercise a peremptory challenge, be it by either the trial court or a juror through concealing material facts, is not a mere matter of procedure, but the deprivation of an absolute and substantial right historically designed as one of the chief safeguards of a defendant against an unlawful conviction. . . . . . . And a presumption of prejudice arises from any jury misconduct . . . ." (Id. at pp. 933-934.) It held "the juror's failure to correctly respond to voir dire questions having a substantial likelihood to disclose facts showing a strong potential for juror bias prevented the defendant from intelligently inquiring into an area of potential bias upon which to base a challenge for cause or to knowingly exercise one of his remaining peremptory challenges." (Id. at p. 930.) The judgment was reversed "because the concealment of the fact the juror had been a victim of the same crime with which the defendant was charged is so directly related to potential juror bias and because the presumption of prejudice arising from the jury misconduct has not been rebutted . . . ." (Ibid.)