SO LONG AS DECLARANT IS AVAILABLE AS WITNESS, HIS STATEMENT SHALL NOT BE HEARD
The reason for the hearsay rule is that extrajudicial and unsworn statement of another is not the best method of serving this purpose. The great possibility of the fabrication of falsehoods, and the inability to prove their untruth, requires that the doors be closed to such evidence. So long as a declarant is available as a witness, his extrajudicial statement should not be heard.
However, where the declarant is dead or has disappeared, his previous statements out of court, if not inadmissible on other grounds, are the best evidence. They are not rendered inadmissible by the mere fact that the declarant is unavailable so long as the declaration was against the declarant’s interest.