What is the reason given by the trial court for the physical restraint of a witness?

The only explicit reason given by the trial court for the restraints was that it had spoken with the bailiff and determined "we cannot maintain security" without them. The contents of the court's conversation with the bailiff were not disclosed. There are no facts in the record to support the conclusion that these witnesses posed a threat of violence or nonconforming conduct in the courtroom. Absent such a showing, the imposition of physical restraint was improper and the court erred in so ordering. (Cf. People v. Valenzuela, supra, 151 Cal.App.3d at pp. 195-196, 198 Cal.Rptr. 469.)

c. Harmless error.