What is the difference between a police lineup and a confession?

A federal case touches on the issue of this case. (Williams v. United States (1969) 136 U.S.App.D.C. 158, 419 F.2d 740, 742.) However, federal law in this area is based on a judicially declared rule and not on a constitutional ground such as is true in California under Article I, section 14 and the supplementary statutes.

Although a confession obtained during an improper delay in arraignment is not automatically prejudicial to a defendant, we feel that the situation is otherwise when the accused is subjected to a lineup without counsel during the period of delay. While there is no essential connection between the illegal detention and the confession, the same is not true in the case of the lineup. Had the defendant been arraigned promptly, he would have had an absolute right to counsel at his lineup, and the results of that lineup would have been Per se excludable since no counsel was present (Gilbert v. State of California (1967) 388 U.S. 263 272--273, 87 S.Ct. 1951, 18 L.Ed.2d 1178).

There are other differences between lineups and confessions. There is no constitutional right to refuse to participate in a lineup since the privilege against self-incrimination (applicable to the confession) does not apply to the lineup. (United States v. Wade, supra, 388 U.S. 218, 87 S.Ct. 1926, 18 L.Ed.2d 1149.) Unlike a confession, almost every identification is pregnant with the seed of error. Ordinarily, a witness can be tested in the courtroom by considering the probability of his 'story', by observing his demeanor, and by vigorous cross-examination. This is exceedingly difficult in identification cases since there is no 'story' because the evidence of identification rests on a single piece of observation. Furthermore, the witness in an identification situation may be wholly convinced of the correctness of his identification and yet be wrong.