State v. Jones

The issue presented is whether the facts upon which an expert bases an opinion concerning the mental status of a defendant must be perceived by the expert or admitted in evidence.

Jones contends that the court of appeals correctly applied Chapin, supra, and that opinion testimony by an expert witness must be based upon facts within the witness’ own personal knowledge or upon facts shown by other evidence.

In Chapin, the court addressed the issue of whether a psychiatrist appearing as an expert witness may testify about contents of writings which he did not prepare but which aided him in…