The court erred in instructing the jury regarding the late disclosure of defense witness statements in an attempted murder prosecution, where the late disclosure could not be attributed to any conduct by the defendant. At trial, the prosecutor had complained that the defense had not disclosed alibi witnesses in a timely fashion. Defense counsel explained that he had turned the statements over as soon as he received them from the defense investigator, but that he had not received the reports until approximately a month after the witnesses were interviewed. The trial court allowed the witnesses to testify, but instructed the jury under CALJIC No. 2.28 to the effect that “defendant failed to timely disclose” the witness’s statements, and that the “weight and significance of any delayed disclosure” were matters for the jury’s consideration. The Court of Appeal first found that it was misleading to suggest that the defendant himself bore any responsibility for the late discovery. Further, the court found that the instruction left the jury without guidance as to how a late disclosure should affect their deliberations. The court noted that in an appropriate case a jury could conclude that a defendant who has disclosed evidence in an untimely fashion has attempted to present a contrived defense, but only if the jury could find that the defendant was personally culpable for the late discovery. Because it was reasonably probable that the defendant might have achieved a more favorable result had the instruction not been given, reversal was required.