Mug Shots

Interference

Interference, in mug shot research, is when postcrime information, in the form of viewing many new faces, weakens or interferes with the witness's memory of the actual criminal. Interference is most commonly tested in research laboratories by exposing two groups of participants to a mock crime, asking one group to look through mug shot photographs and then asking both groups of witnesses to make an identification of the criminal from a six-person lineup. Researchers also manipulate whether or not the mock criminal's photograph is present in the lineup to test whether or not witnesses who viewed the mug shots are more likely to choose an innocent person when the actual target is not present. Although it is reasonable to assume that the process of viewing hundreds of faces in search for a [Page 522]criminal may influence a witness's ability to later make a correct identification of the criminal, research results to do not support this assumption. Research has shown that viewing mug shots has virtually no effect on later identification accuracy from lineups.

Unconscious Transference

Unconscious transference from viewing mug shots refers to the event in which an innocent lineup member, who is also the only lineup member previously viewed by the witness in a prior mug shot task, seems more familiar than do the other lineup members because he was viewed in the mug shots. The concern is that this sense of familiarity on the part of the witness may lead to an increased rate of selection of the (only) lineup member who was seen previously in a mug shot task. The phenomenon of unconscious transference has likely plagued most adults at one time or another as evidenced in the common question, “Where do I know that face?” For witnesses who view mug shots, followed by a lineup that contains one person seen in those mug shots and five photographs never seen before, they are faced with a similar question. The correct answer is for witnesses to say, “I saw that face in the mug shot task,” and the erroneous conclusion is that the face is familiar because it is the face of the criminal.

Support for unconscious transference from mug shots is mixed, with only a few published studies finding support for the effect. Researchers have manipulated variables such as the number of mug shots viewed (from 10 to more than 600) and the delay from viewing the mug shots to the lineup task (immediately to several weeks later) but have been unable to find a consistent predictor of the unconscious transference effect.

...