Trial court may exclude hearsay basis evidence relied upon by expert when the potential the jury will use the evidence for an improper purpose outweighs its probative value. Miller shot and killed his sister’s boyfriend, Neuer. At Miller’s murder trial the defense focused on his mental state, presenting the testimony of a forensic psychologist, Cushing, that Miller suffered from paranoid schizophrenia and shot Neuer as the impulsive reaction to a perceived threat. He was convicted of first degree murder and burglary. On appeal, Miller claimed the trial court erred in precluding Dr. Cushing from disclosing certain out-of-court statements found in another psychologist’s report which related events surrounding the killing, and which were generally exculpatory. Held: Affirmed. An expert may testify as to matters which he relied upon in forming his opinion, including out-of-court statements, when the matter is of a type which may be reasonably relied upon by an expert. (Evid. Cod, §§ 801, subd. (b), 802). This does not transform inadmissible evidence into proof of any fact and juries are so instructed. In some cases, however, a limiting instruction is insufficient to alleviate the risk the jury will use the inadmissible expert basis evidence improperly. The trial court must weigh the relative reliability of the inadmissible evidence and its necessity to the jury’s understanding of the basis for and credibility of, the expert’s opinion against the risk the evidence will be used improperly (Evid. Code, § 352). For confrontation clause purposes, when an expert relies upon hearsay basis evidence as true and testifies as to that evidence, the statements are admitted for their truth. Thus, “when the hearsay basis evidence is case specific, trial judges should be particularly hesitant to admit it.” Here, the exclusion of Miller’s statements in the report relied upon by Dr. Cushing was appropriate because they specifically related to the evidence and the defense theory. Further, the statements were unreliable and self-serving.