When will a judge instruct the jury on the limited purpose for which evidence of other crimes or wrongful acts is admitted?

When evidence of other crimes or wrongful acts is admitted to show the intent of a defendant to commit the offense charged, the judge should ordinarily instruct the jury on the limited purpose for which the evidence is admitted. United States v. Sangrey, 586 F.2d 1312, 1314 (9th Cir. 1978). Limiting instructions may reduce or eliminate prejudice which would otherwise occur. Giving such instructions is but one factor in deciding whether there has been an abuse of discretion. United States v. Brown, 562 F.2d 1144, 1148 (9th Cir. 1977).