Forensic Art

Forensic art refers to the application of artistic skills such as drawing and image modification to legal investigations. Primarily these artistic methods are applied to legal investigations for the purpose of identification, whether that be in attempting to name an unidentified victim when human remains have been found, or identifying and ideally tracking down a suspect based on eyewitness testimony or surveillance footage.

Composite Drawings
Perhaps the most well-known task undertaken in forensic art is that of the composite drawing. These drawings are typically hand-drawn images of a suspect or victim, though more modern methods may involve the artist drawing using a computer/tablet screen and stylus. A particular challenge of composite drawings is that, unlike portraits, they typically involve the production of an image based solely on eyewitness testimony. The artist will interview the witness and ask them to describe the suspect to the best of their ability. The artist will often take into account the witness’ input as he or she draws, making erasures and additions as needed. Inevitably there are a great deal of inaccuracies associated with eyewitness accounts and the ability of an individual to recall a face, coupled with that person’s ability to relay what they have seen (or believe they have seen) and the artist’s ability to recreate this, composite drawings are by no means an accurate, scientific process.

The primary aim of the composite drawing is to provide an identity, either for use solely within a police force or to be distributed amongst the general public. Even if the drawing produced is merely a likeness to the actual individual it is portraying, it might just be sufficient to trigger the memory of another eyewitness who could then contact investigators and assist. They are not a means of positively identifying a suspect, but may be useful as a tool of elimination or corroboration.

Alternatively, composite sketches can be produced with the use of software, such as E-FIT and FACES. This allows the operator, under the direction of the witness, to choose from a range of facial components in order to build up a likeness of the suspect. These pieces of software contain dozens if not hundreds of styles of facial features, allowing the operator to manipulate face shape and size, eyes, the nose, ears, mouth and various other aspects of the human face. Computer software is increasingly being used in other ways, with hopes of developing a reliable system that could compare a drawn facial composite with mugshots of known offenders.

Age Progression
After a certain amount of time has passed in a case, for instance a missing person investigation or another unsolved crime, existing photos of victims or suspects will eventually become outdated, rendering the distribution of an old photo relatively futile. In this instance, if the individual is believed to still be alive, a technique known as age progression might be used. As the name suggests, this essentially involves manipulating the image of an individual (or producing a hand-drawn sketch) to portray what that individual may look like now after, for example, 20 years of ageing. This ageing process may involve the addition of wrinkles, changes in skin texture, recession of the hairline, loss of hair, and changes in facial shape. Modern clothing and hairstyles may be used, but these are best kept relatively generic so as not to draw attention away from the face.

Predictably, it is not possible to accurately determine exactly how an individual will age and what they will now look like. However using knowledge of facial ageing patterns, facial anatomy, and as much information about the person as possible, a reasonable estimation can be made. A variety of factors may be taken into account, including family details such as how their parents and siblings have aged (particularly if ageing a child), lifestyle such as if they maintained a healthy diet or if they are likely to have gained weight and if they smoked, personal habits or particular facial expressions, and where they may have moved to. Of course there are a variety of factors that the artist cannot possibly take into account, such as hair colour and style, facial piercings, facial hair, injuries and scars obtained since the person was last seen, and cosmetic surgery. However this at least may succeed in opening up new lines of inquiry or at least renewing the interest of the public and media.

Post-Mortem Images
Following death, a drawing or photograph of an individual may be created and/or retouched in such a way that the image is suitable for public display. For instance, in the case of an unidentified victim who has suffered significant injuries or severe decomposition, modifications may be made to restore the original appearance of the individual as best as possible, whilst attempting to eliminate any signs of injury or death that may be upsetting.

Facial Reconstruction
The term facial reconstruction typically refers to the reconstruction of an individual’s face, often using underlying bone structure as a basis, carried out by a forensic anthropologist and/or a forensic artist. This may be carried out when badly decomposed or completely skeletonised remains are under investigation, and an approximation of the individual’s face is required for identification purposes. The reconstruction of a face can be 2D or 3D. A common method of 3D reconstruction utilises clay, which is placed over a replica of the skull and moulded. The depth of the clay, or ‘flesh’, is established by the placement of a number of tissue markers placed at specific anthropological landmarks on the facial plane of the skull. If the remains are not yet entirely skeletonised and some soft tissue remains, determining likely flesh depth may be somewhat less difficult. There are a number of calculations that the artist or anthropologist can carry out to estimate the size and depth of certain facial features, however these calculations typically assume that sex and race have already been established. After the soft tissue has been added, additional features should as lips, the nose, ears, eyes and hair can be added, though of course the addition of these features require a certain amount of guesswork. More recently, 3D reconstructions can be carried out using specialist computer software. Unfortunately there are many inaccuracies associated with facial reconstruction. Apart from the process being extremely subjective and difficult to reproduce, there is a severe lack of data (regarding average tissue thickness for instance) and in many countries a lack of method standardisation.

 

B. Klare, S. Klum, J. Klontz, E. Taborsky, T. Akgul, A. Jain. Suspect Identification Based on Descriptive Facial Attributes. International Joint Conference on Biometrics, 2014.

Forensic Magazine. Forensic Art: Age Progression. [online] Available: http://www.forensicmag.com/articles/2009/02/forensic-art-age-progression

Ask A Forensic Artist. [online] Available: http://www.askaforensicartist.com