In lieu of an abstract, below is the article's first paragraph.
We've all experienced, at one time or another, our own memories failing us at times, and this may have been due to a number of factors. Perhaps the issue at hand was not important to us at the time, and therefore we devoted little attention to it. But imagine being in the scenario Wells (1993) suggests in the following passage:
Suppose that you were an eyewitness to a crime. Perhaps it was a theft, a burglary, a mugging, a drive-by shooting, or a robbery. You might or might not have known that a crime was being committed at the time; perhaps you saw someone exit a building that exploded a short time later. Perhaps you were the victim or perhaps you were a bystander. Regardless of the circumstances, there exists some memory trace, however strong or weak, that could have important consequences for the course of justice. Because you have seen the culprit, the police ask you to give a description. Later, perhaps only hours or perhaps months later, you are called to the police station to attempt an identification of the culprit. You are then shown a lineup or a photo spread and asked to indicate whether the person you saw on that fateful occasion is one of the people standing or pictured before you on this day. (p. 553)
Many factors influence the accuracy of recall and identity of a face, some of which we have little to no control over. Given the right conditions, these factors will influence how one's memory recalls the specific features that make one face distinct from another.
Lorenza, Sheena M.. "Factors Affecting the Accuracy of Eyewitness Identification." The Review: A Journal of Undergraduate Student Research 6 (2003): 45-50. Web. [date of access]. <http://fisherpub.sjfc.edu/ur/vol6/iss1/9>.