Latent fingermarks and DNA recovery

Matching a questioned fingermark from a crime scene with a suspect is one of the ways of achieving human identifications. However, if a fingermark is partial, distorted, or blurry beyond recognition, this task becomes more challenging, and sometimes cannot be attained solely based on fingermark ridge patterns. As a result, an alternative human identification approach will be necessary. Latent fingermarks are one of the sources of what has been named "touch DNA", DNA left as a result of touching objects. Thus, DNA recovered from a fingermark can be used as another source of identification to confirm the results of a fingermark comparison and vice versa. There have been several studies that have focused on "touch DNA"/ fingermark DNA in recent years. Some of these experiments investigated the source of this DNA and the factors that could affect its recovery, such as shedder status, environmental conditions, and time since deposition. Other studies concentrated on improving the techniques of DNA recovery and amplification along with other works that analyzed the potential interference of fingermark enhancement methodologies on DNA retrieval. This chapter presents an overview of the state-of-the-art technologies on DNA recovery, amplification, and profiling from "touch DNA"/ fingermark DNA.