If a suspect is not advised of his Miranda rights prior to making his custodial statement, can the state compel the suspect to remain silent?

If, however, a defendant is not advised of his Miranda rights prior to making his custodial statement, an irrebuttable presumption of compulsion arises and the state cannot show that the suspect waived his rights voluntarily. Oregon v. Elstad, 470 U.S. 298, 307, 105 S.Ct. 1285, 84 L.Ed.2d 222 (1985). A trial court's conclusions regarding the constitutionality of a defendant's waiver of his right to remain silent is reviewed de novo on appeal; the underlying findings of fact are reviewed for clear error. See United States v. Spencer, 995 F.2d 10, 11 (2d Cir.1993) (per curiam).