Kostadinov v. United States

How later courts describe this case

• noting that Rule 804(b)(1)'s concern for adversarial cross-examination is not present when the government has had a previous opportunity to question a witness during a grand jury hearing
• noting that requirement that court rule upon validity of witness’ assertion of privilege need not be met when its fulfillment would be mere formalism
• “it is clear that a witness who is unavailable because he has invoked the Fifth Amendment privilege against self-incrimination is unavailable under the terms of 804(a)(1)”