Evidence
Relevance, Character, and Hearsay
Evidence must be relevant, meaning it tends to make a fact of consequence more or less probable. Relevant evidence may still be excluded under Rule 403 if unfair prejudice, confusion, or delay substantially outweighs probative value. Character evidence is generally inadmissible to prove propensity, but the accused may offer character evidence in a criminal case, and the prosecution may rebut it. Evidence of other crimes may be admitted for motive, intent, absence of mistake, identity, or common plan.
Impeachment methods include bias, prior inconsistent statements, reputation for truthfulness, and criminal convictions. Prior inconsistent statements given under oath may be substantive evidence; other prior inconsistent statements are only impeachment. Hearsay is an out-of-court statement offered for its truth. Nonhearsay uses include effect on the listener, verbal acts, and state of mind.
Common exceptions include present sense impression, excited utterance, then-existing condition, business records, public records, dying declarations, and co-conspirator statements. Testimonial hearsay implicates the Confrontation Clause unless the declarant is unavailable and the defendant had a prior opportunity to cross-examine. Expert testimony requires reliable methods and fit; authentication requires sufficient evidence that an item is what it purports to be. The best-evidence rule requires the original writing to prove its contents, with exceptions.
Traps and Rule of Thumb
A frequent trap is admitting a prior consistent statement as substantive evidence without a hearsay exception. Rule of thumb: ask who made the statement, when, and why it is offered. If offered for truth, find an exception.