“ Moreover, unlike the Simmons case, identification here rested hargely on voice. The fact that petitioner had 'the voice of an immature youth,' to use Mrs. Beamer's words, merely put him in a large class and did not relate him to speech peculiar to him. Voice identifications involve 'grave danger of prejudice to the suspect,' as the Court of Appeals for the Fourth Circuit said in Palmer v. Peyton, 359 F.2d 199, 201. No one else identified petitioner. The daughter could not; and Mrs. Beamer did not identify him in the courtroom. Petitioner was young and apparently had no previous police record. ”

“ Petitioner stood to be free of the charge or to account for it, dependent on what Mrs. Beamer said. Whatever may be said of lineups, showing a suspect singly to a victim is pregnant with prejudice. The message is clear: the police suspect this man. That carries a powerfully suggestive thought. Even in a lineup the ability to identify the criminal is severely limited by normal human fallibilities of memory and perception. When the subject is shown singly, havoc is more likely to be played with the best-intended recollections. ”

“ Of course, due process is not always violated when the police fail to assemble a lineup but conduct a one-man showup. Plainly here, however, the highly suggestive atmosphere that had been generated by the manner in which this showup was arranged and conducted could not have failed to affect Mrs. Beamer's judgment; when she was presented with no alternative choices, 'there (was) then a strong predisposition to overcome doubts and to fasten guilt upon the lone suspect.' Palmer v. ”