Hearsay evidence is inadmissible.

United States v. Geiger, 263 F.3d 1034, 1038-1039 (9th Cir. 2001) (upholding trial court's admission of arresting officer's prior testimony at the federal suppression hearing because "[u]nder Rule 804(b)(1), prior testimony....The hearsay exception for prior testimony applies in a criminal case only if the if the party against whom the testimony is now offered had an opportunity and similar motive to develop the testimony in the prior proceeding by direct, cross, or redirect examination. The exception applies in a civil action or proceeding only if the party against whom the testimony is now offered or a predecessor in interest had an opportunity and similar motive in the prior proceeding to develop the testimony by direct, cross, or redirect examination.

United States v. Lillard, 354 F.3d 850, 854 (9th Cir. 2003) (upholding trial court's admission into evidence of accused's theft of cocaine because it was inextricably intertwined with the conspiracy crime as it established the elements of identity and knowledge ).Other crimes, wrongs, or acts are admissible and do not violate the prohibition against the use of character to show conduct if such acts are admissible to show the context of an event at issue at trial or to tell the full story or an intelligible story of a series of events at issue at trial.

Michelson v. United States, 335 U.S. 469, 475-476 (1948) ("Courts that follow the common law tradition almost unanimously have come to disallow resort by the prosecution to any kind of evidence of a defendant's evil character to establish a probability of guilt. Not that the law invests the defendant with...A person's character, or propensity, is inadmissible to show that person's conduct on a specific occasion.