What is the effect of making a public statement as a witness in a criminal investigation?

1 As was said in United States v. Ewell, supra at 120, 86 S.Ct. at 776, the Sixth Amendment guarantee "is an important safeguard to prevent undue and oppressive incarceration prior to trial, to minimize anxiety and concern accompanying public accusation and to limit the possibilities that long delay will impair the ability of an accused to defend himself."

2 The familiar example is found in narcotics investigations where the efficacy of an undercover agent or informant to penetrate the network of illicit distribution ceases when he publicly appears as complainant. See, e. g., United States v. Simmons, 338 F.2d 804 (2 Cir. 1964), cert. denied, 380 U.S. 983, 85 S.Ct. 1352, 14 L.Ed.2d 276 (1965).