California Evidence Code section 1221
Evidence Code section 1221 provides:
"Evidence of a statement offered against a party is not made inadmissible by the hearsay rule if the statement is one of which the party, with knowledge of the content thereof, has by words or other conduct manifested his adoption or his belief in its truth."
Such adoption or belief can be manifested either by explicit acceptance of another's statement or by silence or equivocal or evasive conduct. There are two requirements for the introduction of an adoptive admission: (1) the party to whom the statement will be attributed must have knowledge of the content of the statement; and (2) having such knowledge, the party must indicate by words or conduct his adoption of or belief in the truth of the statement. An admission may be deemed adopted by silence when a party is accused of committing a crime, under circumstances which afford him an opportunity to hear, understand and to reply and when a response would normally be expected if the statement were untrue. (People v. Combs (2004) 34 Cal.4th 821, 842-843; People v. Riel (2000) 22 Cal.4th 1153, 1189.)
A statement may be admitted as an adoptive admission when the evidence supports a reasonable inference that the statement was made under the required circumstances noted above. If that inference exists, then whether the statement is an adoptive admission is question of fact for the jury. (People v. Riel, supra, 22 Cal.4th at pp. 1189-1190.)
The decision to admit hearsay evidence and to determine the elements necessary for its admission rests in the discretion of the trial court and on review an exercise of that discretion will not be overturned absent an abuse of that discretion. (People v. Guerra (2006) 37 Cal.4th 1067, 1113; People v. Pirwani (2004) 119 Cal.App.4th 770, 787.)