A defendant’s testimony given at a motion to suppress evidence may be used at trial to impeach his expert witness. Appellant was convicted of several sexual offenses against a child and was sentenced to 55 years to life in prison. On appeal he challenged the trial court’s order allowing the prosecution to impeach his expert witness (a psychologist who testified about appellant’s limited educational/writing ability in support of a false confession defense and whose opinion was based in part upon discussion with the appellant) with a transcript of appellant’s pretrial Penal Code section 1538.5 hearing testimony. Held: Affirmed. The trial court denied appellant’s suppression motion, finding his statements were voluntary. Therefore, use of his suppression hearing testimony did not violate the holding in James v. Illinois (1990) 493 U.S. 307, which precludes the use of illegally obtained custodial statements to impeach defense witnesses other than defendant. While defendant’s testimony at a motion to suppress generally may not be admitted over objection to prove guilt (Simmons v. United States (1968) 390 U.S. 377, 389), this prohibition does not apply where the testimony is relevant to impeach his credibility. Allowing the defendant’s suppression testimony to impeach his expert witness best promotes truth-seeking and does not chill a defendant from presenting a defense through the testimony of others, nor does it encourage police misconduct.

Permitting the prosecution to ask its expert whether any evidence disproved defendant’s guilt was harmless error. In a question to its child abuse expert physician, the prosecution asked whether any evidence the expert considered contradicted the minor’s claims that defendant sexually assaulted her. Although the question asked the expert to testify directly about defendant’s guilt and was improper, any error in allowing it was harmless in light of the remaining evidence.

Allowing both a victim advocate and a therapy dog to accompany the minor to the witness stand did not violate state law or due process. Over objection, the court advised the jury it would allow the minor complainant to be accompanied to the witness stand by an advocate from the prosecutor’s office, as well as a therapy dog. A support person’s presence with a testifying witness pursuant to Evidence Code section 868.5 does not infringe upon a defendant’s right to due process unless the advocate interferes with the witness’s testimony in a manner which adversely affects the jury’s ability to consider the evidence. The additional presence of the therapy dog did not violate the “one support person” language of section 868.5 because the therapy dog is not a “person” within the meaning of the statute. The trial court appropriately exercised its discretion under Evidence Code section 765, subdivision (b) when it allowed the child victim to have a therapy dog with her during her testimony.