Foster (D) was charged with the armed robbery of a Western Union office. Other than the robbers, the only witness to the crime was David, the late-night manager of the office. One of the robbers surrendered to the police and implicated D and Grice. David viewed a lineup of three men. D was tall, and the other two men were short by six inches. David could not positively identify D. He 'thought' he was the man, but he was not sure. David then spoke with D at a table. Except for prosecuting officials, there was no one else in the room. David still was uncertain. A week or 10 days later, the police arranged for David to view a second lineup. There were five men in that lineup. D was the only person in the second lineup who had appeared in the first lineup. This time David was 'convinced' D was the man. D and Grice were tried together. Grice was acquitted. D was convicted. The Court of Appeal affirmed the conviction; the State Supreme Court denied review. The Supreme Court granted certiorari, limited to the question whether the conduct of the police lineup resulted in a violation of petitioner's constitutional rights.