A woman is found dead in her bed with a gunshot wound to the head. Her sister tells police that she believed the woman's husband must have shot her. She then gives the police investigator a sealed letter postmarked a year earlier that she received from her sister with instructions to open only if "something happens to me." The investigator opens the letter and reads that the dead woman believed her husband was planning to kill her and had threatened to shoot her while she slept.

a. Can the letter be admitted into evidence?

b. If you represent the husband, what argument will you make to keep the letter out of evidence?