What is the current state of the law on the right of a witness not to confront a defendant in a witness box?

"It is the likelihood of misidentification which violates a defendant's right to due process . . . . Suggestive confrontations are disapproved because they increase the likelihood of misidentification, and unnecessarily suggestive ones are condemned for the further reason that the increased chance of misidentification is gratuitous. But . . . the admission of evidence of a showup without more does not violate due process." (Neil v. Biggers (1972) 409 U.S. 188, 198 [34 L.Ed.2d 401, 410-411].)