Prosecution of D for bank robbery. D denies involvement. A few days before trial, X, an eyewitness who would have identified D as the perpetrator, suddenly left the country for a foreign destination. X refuses to return and is beyond the court's subpoena power. The prosecution calls PO, a police officer, to testify that shortly after the robbery, X told PO that she saw D rob the bank. D objects on hearsay grounds. The prosecution responds that D threatened to kill X unless X left the country. How should the court rule on D's hearsay objection, and why?