Alvarado

In this case we must determine the validity of an order, entered prior to trial in a criminal action, that authorizes the prosecution to refuse to disclose to the defendants or their counsel, both prior to and at trial, the identities of the crucial witnesses whom the prosecution proposes to call at trial, on the ground that disclosure of the identities of the witnesses is likely to pose a significant danger to their safety.

Protecting the safety of witnesses unquestionably is of the utmost importance, and a trial court has broad discretion to deny, restrict, or defer disclosure of a witness’s identity prior to trial in order to provide such protection (Pen. Code, § 1054.7). As we shall explain, however, we conclude in light of controlling constitutional authorities that the trial court and the Court of Appeal erred in determining that, when the risk to a witness is sufficiently grave, the identity of the witness may be permanently withheld from a defendant and the witness may testify anonymously at trial—even when the witness is a crucial prosecution witness and withholding the witness’s identity will impair significantly the defendant’s ability to investigate and…