## Facts

- A truck was stolen from Timothy Sterns’s workplace on May 20, 1994.
- Police searched Mario Amado Terrazas’s property with his consent and found the stolen truck’s frame and glove box containing the vehicle identification number; Sterns later identified additional seized parts as his.
- Terrazas stated he had been away for four days and that an unknown person left the vehicle parts on his property.
- In a bench trial for theft, the prosecution offered other-acts evidence under Arizona Rule of Evidence 404(b) involving alleged connections to stolen vehicles.
- The trial court admitted evidence tied to (1) a prior theft where a witness saw a stolen vehicle driven onto Terrazas’s property and parts were found there, and (2) a prior theft where library books from the stolen vehicle were found on Terrazas’s property; it rejected a third incident due to lack of identification.
- The trial court applied a preponderance standard to determine the other acts and found Terrazas guilty; the court of appeals affirmed using the same standard.

## Issues

1. What standard of proof must a trial judge apply when determining whether “other crimes, wrongs, or acts” are sufficiently established for admission under Arizona Rule of Evidence 404(b) in a criminal case?

## Decision

- The Arizona Supreme Court reversed the court of appeals and vacated the conviction.
- The court held that Rule 404(b) other-acts evidence in Arizona criminal cases is admissible only if the proponent proves by clear and convincing evidence that the prior act occurred and that the defendant committed it.
- Applying that standard, the court concluded at least some of the admitted other-acts evidence (including the library-books incident) was not shown by clear and convincing evidence, and its admission was prejudicial even in a bench trial.
- The case was remanded for a new trial.

## Legal Principles

- Other-acts evidence offered under Rule 404(b) is generally inadmissible to prove propensity and poses a substantial risk of unfair prejudice.
- In Arizona criminal cases, before admitting Rule 404(b) evidence, the trial judge must find by clear and convincing evidence that the other act occurred and that the defendant committed it.
- Arizona rejects the federal preponderance approach associated with Huddleston for purposes of establishing the foundational proof required to admit other-acts evidence.
- The risk that a factfinder will misuse other-acts evidence exists in bench trials as well as jury trials; erroneous admission may require reversal when the trier of fact considered the evidence in finding guilt.

## Conclusion

The court required a clear and convincing evidentiary showing that a defendant committed a prior bad act before Rule 404(b) evidence may be admitted in Arizona criminal trials, reversed the conviction because that standard was not met for key other-acts evidence, and ordered a new trial.


State v. Terrazas, 189 Ariz. 580, 944 P.2d 1194 (Ariz. 1997)