Older individuals have been found to exceed young adults in false recognitions on line-up tasks. To explore factors involved in this deficit, a study compared effects of post-event information and sequential line-up presentation on false identification by young and elderly adults. Ninety-eight community-dwelling older adults (ages 57-83) and 97 college students (ages 19-33) saw a videotape of a simulated crime, then heard an auditory narrative. Some heard a review of the events of the crime (including some misinformation) and others heard a control narrative that was unrelated to the video. Participants recalled the crime and then saw either a simultaneous or sequential target-absent line-up. Sequential line-ups reduced false identification rates for young and elderly adults. Hearing a relevant post-event narrative increased false identifications, but only in the older group. For the elderly, high verbal recall of the perpetrator's characteristics was also associated with higher false identification rates. Results suggest that reducing post-crime exposure to crime-relevant information, combined with sequential line-ups, can substantially reduce false identification by older witnesses. They also indicate the need to explore further the influence of post-event information, sequential line-up presentation, availability, and self-confidence upon older eyewitnesses. Tables, notes, references