In Michigan v. Jackson, 475 U.S. 625, 635, 106 S. Ct. 1404, 1411, 89 L. Ed. 2d 631, 642 (1986), the United States Supreme Court applied the Edwards exclusionary rule (Edwards v. Arizona ) to the Sixth Amendment, holding that a defendant who requested counsel post-indictment had a Sixth Amendment right to have counsel at any police interrogation. The Court stated: Edwards is grounded in the understanding that 'the assertion of the right to counsel is a significant event,' and that 'additional safeguards are necessary when the accused asks for counsel.' We conclude that the assertion is no less significant, and the need for additional safeguards no less clear, when the request for counsel is made at an arraignment and when the basis for the claim is the Sixth Amendment. We thus hold that, if police initiate interrogation after a defendant's assertion, at an arraignment or similar proceeding, of his right to counsel, any waiver of the defendant's right to counsel for that police-initiated interrogation is invalid. Ibid.