The application of artistic methods to legal investigations, forensic art is primarily used in the identification of victims and suspects. This may be to aid police searches, jog the memories of witnesses to an incident, or for wider distribution. Additionally, the artist may be involved in providing artistic evidence for courtroom presentations, the sketching of crime scenes, and the modification or enhancement of images.
A common task carried out by the forensic artists is the drawing of potential suspects or victims. These are basically freehand sketches completed by the artist based on all available pieces of information. The head is divided up into various portions; the head is halved horizontally, and then halved twice more below this line. These lines give the approximate position of the eyes, nose and mouth, which the artist can alter depending on the information given to them.
The process will generally begin with an interview with the witness or victim, during which they will describe the appearance of the subject to the best of their ability. Using this information, the artist can compose a sketch of likeness. The witness will be invited to view the sketch throughout the process so that they may request any alterations be made if the image is not accurate. These sketches can also involve any relevant distinguishing features such as tattoos, scars, jewellery, clothing and distinctive hairstyles or facial hair. Once the composite drawing has been completed, the image can be distributed amongst law enforcement agencies and even members of the public via the media.
These composite sketches are not considered to be an exact portrait of the subject, but more an account of the witness’ memory. Whereas they cannot be used to positively identify the suspect, they can be a tool of elimination and corroboration.
One primary type of image modification is photograph ageing, often utilised in cases of missing persons or fugitives who have not been seen for a long time. The most recent photograph available of the subject is taken. Using knowledge of complex craniofacial growth patterns and various other pieces of information, it is possible to alter an image to portray how they will most likely appear now. The expert will often take into consideration the subject’s living environment, family history and genetics, and personal hygiene. However certain factors cannot possibly be established, such as hair colour, style, facial hair, and clothing. This can all be done by hand or using computer software.
Post-mortem imaging is often essential if it is necessary to distribute an image but the victim has suffered great violence or the body has decomposed. The media will not publish or broadcast such a disturbing image or an image of the decedent on a morgue table so as not to distress members of the public. Therefore software is available to edit the background, remove obvious signs of injury or decomposition, and restore natural, life-like features. Such a technique is only appropriate if there is sufficient soft tissue present on the skull. Extensive injury or decomposition will require a facial reconstruction.
In cases involving unidentified skeletal remains, the forensic artist may be required to attempt to identify the victim using facial reconstruction along with an anthropological expert. Initially as much information is gathered as possible, such as race, sex and approximate age.
The facial reconstruction begins with the placement of 21 tissue depth markers on anthropological landmarks on the facial plane of the skull. These markers represent the average depth of facial tissue for individuals of the same race, sex and age of the victim. These markers are placed based on research by Rhine & Campbell (1980) which studied cadavers whilst taking into consideration muscle, fatty and connective tissue, and skin thickness at particular points on the skull. Strips of clay are positioned on the skull following the suggestion of the tissue markers. Once the basis of the face is complete, other features can be added such as eyes, ears, mouth, nose and hair. This process is slow and painstaking, and can often take weeks or even months to complete.
There are however some factors which cannot be assumed by the artist, including weight, hair colour and length, and eye colour. The nose is also difficult to reconstruct, as the underlying bone is fairly limited while variation is potentially great.
If this process is conducted correctly, the result should bear a striking resemblance to the individual. As with composite drawings, an image of the resulting face can then be distributed among law enforcement personnel or to the general public. The reconstructed face should be photographed in such a way that there is no perspective distortion.
An alternative form of identifying a victim using an unidentified skull is superimposition. This technique superimposes a photograph of an individual over an x-ray of the skull. If the skull does indeed belong to the individual, the anatomical features of the face should align accurately with the image. However this is not a positive means of identification, though can act as a useful indicator.
Various pieces of computer software are available for use in legal investigations. Some programs are designed for the purpose of creating a two or three-dimensional likeness from skull bones, aiding in identifying unknown victims.
Computer programs have also been used for creating facial composites, especially in the UK, where computerised composites are preferred to hand sketches. The most commonly used programs in the UK are E-FIT and EFIT-V, which are pieces of software which allow the user to select individual facial features to develop an image of likeness to a suspect. The expert will sit down with the witness and ask them to describe the individual of interest, after which they can produce the image. E-FIT allows the user to select specific individual features to put together into an image. However as the human brain recognises facial features as a whole and not individual parts, the later-released holistic EFIT-V was developed. EFIT-V allows for entire faces to be viewed and features altered as necessary. These programs also allow for the addition of hairstyles, clothes, jewellery and other distinctive features.
When using witness statements to produce an image if likeness to a suspect, the acronym ADVOKATE should be taken into consideration regarding the reliability of eyewitness testimony (with regards to R v Turnbull 1977).
A – Amount of time suspect was under observation.
D – Distance between the witness and the suspect.
V – Visibility at the time of the incident.
O – Obstructions present.
K – Known or scene before by the witness.
A – Any specific reason to remember the person or incident.
T – Time elapsed since the incident.
E – Errors or discrepancies in the witness’ statements.
Crime Scene Sketches
A forensic artist may often be called upon to make sketches of a crime scene. Such sketches must include accurate dimensions of the room, the locations of significant objects and items of evidence, distance measurements between objects and two fixed positions, a legend or key as necessary, and a compass designating north.
These sketches will generally be produced at the crime scene by crime scene technicians or law enforcement, however in some cases more intricate designs are required.
Careers & Education
The majority of forensic artists conduct their work in unison with a regular job in law enforcement or forensic services. There are very few full-time forensic artists, and those that do possess full time jobs generally work within large government agencies. Freelance work is difficult to get into due to the legal nature of the work.