Hand identification research. Enhanced digital photography of the upper surface of a person's hand, showing the vein patterns. Vein pattern is being investigated as a possible alternative to fingerprint identification in some criminal cases, especially in child sexual abuse cases where the perpetrators film or photograph themselves committing the crime, usually including shots of their hands. So far studies have found that the shape of the vein pattern on the back of a person's hands is unique, even in identical twins. This, combined with the creases at the knuckles, scars and nail bed shapes, can be used to identify or eliminate suspects.