## Facts

- A triple homicide occurred near Phoenix in December 1977 in connection with a marijuana transaction; the victims’ bodies were burned in a car in the desert.
- The prosecution alleged Dolan Chapple was a participant known as “Dee,” involved in the killings during the drug deal.
- The State’s case linking Chapple to the crimes rested almost entirely on eyewitness identifications by Malcolm Scott and Pamela Buck.
- Scott and Buck did not know Chapple previously and identified him from photographs more than a year after the offense.
- Chapple presented an alibi defense, claiming he was in Cairo, Illinois throughout December 1977, supported by multiple witnesses.
- Over defense objection and despite an offered stipulation on cause of death, the trial court admitted graphic color photographs of a burned victim’s body and wounds.
- The trial court excluded proposed expert testimony from Dr. Elizabeth Loftus regarding general psychological factors affecting eyewitness reliability (without opining on whether the witnesses were correct).

## Issues

1. Whether admitting highly graphic photographs, where cause of death was not disputed, was an abuse of discretion under Rules 401 and 403 because unfair prejudice substantially outweighed probative value.
2. Whether excluding expert testimony on general factors affecting eyewitness identification reliability was an abuse of discretion under Rule 702 in a case turning on disputed identification evidence with little corroboration.

## Decision

- The Arizona Supreme Court reversed Chapple’s convictions and remanded for a new trial.
- The court held the trial court abused its discretion by admitting the gruesome photographs because their slight probative value was substantially outweighed by the danger of unfair prejudice.
- The court held the trial court abused its discretion by excluding expert testimony on eyewitness identification; in this case, the testimony would have assisted the jury and its exclusion was reversible error.
- The court noted the combined effect of inflammatory imagery and restricting the defense’s challenge to the State’s only direct link to Chapple materially impaired trial fairness.

## Legal Principles

- Relevant evidence may be excluded under Rule 403 when its probative value is substantially outweighed by the danger of unfair prejudice; graphic photographs are improper when they add little to proving a disputed fact and primarily arouse juror emotion.
- A defendant’s willingness to stipulate to an undisputed matter (such as cause of death) may reduce the probative need for inflammatory exhibits offered on that point.
- Expert testimony is admissible under Rule 702 when specialized knowledge will assist the trier of fact; expert testimony does not become inadmissible merely because it bears on credibility or because a court fears it will “invade the province of the jury.”
- In cases where identification is central, uncorroborated, and subject to known sources of error (e.g., stress, delay, viewing conditions, suggestive influences), expert testimony on eyewitness reliability may be necessary to provide the jury an adequate basis to evaluate the evidence.

## Conclusion

The court ordered a new trial because the admission of extremely gruesome photographs with minimal disputed relevance, together with the exclusion of expert testimony explaining factors that can distort eyewitness identification, created an unacceptable risk that the verdict rested on emotion and overconfidence in contested identifications rather than careful evaluation of the evidence.


State v. Chapple, 135 Ariz. 281, 660 P.2d 1208 (Ariz. 1983)