Sometimes, but an uncharged act cannot be used merely to argue that you have a bad character and therefore committed the charged crime. Evidence Code section 1101(a) generally bars that character-to-conduct inference. Section 1101(b) may allow a specific other act to prove a genuinely disputed noncharacter issue—such as intent, identity, knowledge or absence of mistake—if the act actually supports that inference. Calling the evidence “intent” or “common plan” is not enough by itself. (Evidence Code § 1101)

The similarity needed depends on the proposed use. People v. Ewoldt explains that intent generally requires less similarity than a common plan, while identity requires distinctive similarities. Even if an act has a proper purpose and is relevant, the court must separately consider Evidence Code section 352: it may exclude evidence when its probative value is substantially outweighed by undue consumption of time, undue prejudice, confusion or the risk of misleading the jury. (People v. Ewoldt; Evidence Code § 352)

Compare the claimed inference with the proof

Ask what exact fact prosecutors say the other act proves, what evidence supports that act, and which features connect it to the charged conduct. The comparison should focus on the purpose offered: features that might support intent may not be distinctive enough to support identity. A nonpropensity label does not guarantee admission, and the other act need not have resulted in a conviction for the court to consider it. Remoteness, proof disputes, time and the risk that jurors will use the act as character evidence can matter in the section 352 analysis.

Some prosecutions have separate statutory propensity provisions. Section 1108 addresses qualifying other sexual offenses in covered sex-offense cases, and section 1109 addresses qualifying other domestic violence or abuse in covered cases; each has its own conditions and remains subject to section 352. (Evidence Code § 1108; Evidence Code § 1109) A prior conviction offered to challenge a testifying defendant’s credibility is another distinct question. Do not assume every prior act is admissible or that every propensity use is governed by section 1101(b).

Before trial, gather the prosecution’s notice or motion, the evidence for each alleged act, and the specific purpose offered. Counsel can compare the acts feature by feature, address section 352 separately, and request a ruling or limiting instruction. The court decides admissibility on the record; neither admission nor exclusion follows automatically from the fact that the act was uncharged.

For the firm’s motion-in-limine information, see the practice page. For help evaluating proposed other-act evidence, contact the Law Offices of David S. Chesley at (800) 755-5174.