Forensic Analysis of Facial Components

Forensic artists can recreate faces from skeletal remains.

First suggested over a hundred years ago, facial recognition techniques have advanced dramatically with the advent of the digital age. With image capturing technology proliferating---from cell phone cameras to public CCTV systems---the means of using the images to identify individuals has improved. Facial analysis has several applications in the realm of forensics.

History

In 1885, Alphonse Bertillon published "Signaletic Instructions Including the Theory and Practice of Anthropometrical Identification," which suggested that a set collection of body measurements be used for identification purposes. Three classifications he proposed were measurements of the body, the relationship between the body and movement and marks on the surface of the body, such as scars, warts and tattoos. He also proposed using the ear as an identifier, citing four characteristics which could be used as a means of cataloging them. He never suggested any single bodily feature could be used to successfully identify people but rather a number of features must be collected together. Modern methods use a collection of features to achieve positive identification.

Function

There are two uses for facial analysis---identification and verification. Identification is the act of ascertaining an individual's identity while verification is the process of determining if the given identity is accurate. Identification involves comparing one image against many---narrowing the matches to the positive one. Verification is comparing one against one, determining whether the identification is accurate.

Uses

Facial component analysis techniques are used in a variety of ways by forensics professionals. Facial reconstruction allows forensic artists to recreate a face from skeletal remains. They may achieve this by using photographic superimposition. This is the process of comparing a photograph to the skeletal remains to see if the components will match. Images can be artificially aged to illustrate the passage of time in the cases of missing persons or individuals with no recent photographs available. Facial recognition software can be used to identify individuals from video footage taken from any of a variety of sources. With growing computer capabilities, much of this work is done digitally.

Types

The facial features commonly used for identification or image generation are the shape and size of the supraorbital ridges (the area above the eye), characteristics of the nasal area, signs of healed injuries and unusual dental characteristics. While these are not the only features to be used, they are the most common.

Benefits

Identification can be used not only for determining the identity of a suspect but also that of the victims. By publicizing the likeness of suspects, citizens are able to offer tips to law enforcement. By determining the identity of an unknown victim, the chances of identifying the perpetrator increase.

References

• Forensic Evidence: Alphonse Bertillon
• Federal Bureau of Investigation: Facial Recognition