This article reports on research of digitally altering lineup photographs to add or remove distinctive facial features. The reason behind this is that if the witness or victim recalls a distinctive facial feature such as a scar, there is a
tendency for them to focus just on that feature. So, if the police pick
up an innocent person who has a similar feature, the eyewitness is likely to mistakenly identify the innocent person on the basis of
this feature. This technique would either remove the scar from all of the photos in the lineup or add a scar to all of the photos in the lineup. It turns out that adding the same distinctive feature to each of the
faces led to more accurate performance than removing the distinctive
feature. People correctly identified the face they had seen about 50%
of the time when all of the faces had the distinctive feature, but they
identified it correctly only about 30% of the time when the distinctive
feature was removed from the target face.
He had a big scar
He had a big scar
This is kinda of neat because you would think adding a distinctive feature to all the faces would make it harder for the witness to pick out the right person.