My witness in an upcoming Agg. Asslt case has become uncooperative. He's in California and we have been unable to locate him and find a good address to do an out-of-state subpoena. The main reason I would call him is to get the 911 call he made saying my defendant committed the shooting into evidence. Is the fact that he has become uncooperative and we can't find him enough to declare him unavailable under Crawford?

Also, because my case is 4 years old, we are further unable to find the 911 operator. For authenticity purposes, is it enough if I can have one of the victims listen to the 911 call and testify that it is the witness's voice on the recording?

Thanks in advance!