A facial composite is a sketch or computer generated image used to create a visual representation of a suspect based on the memory and description of eyewitnesses. Composite sketches are frequently used to help track down suspects in a crime in which there is no photographic evidence. Though frequently used in both investigative and prosecutorial areas of law, critics suggest that facial composite sketches and the newer computer-generated versions are extremely prone to misuse and error. If judges and juries rely heavily on facial composites to make decisions, critics say that innocent people are at risk of jail and other consequences as a result of mistaken identity.
There are several methods of creating a facial composite. The most basic involves sketch artists, who are often professionals and have many years of training in both art and the craft of compositing. Sketch artists may speak in detail with eyewitnesses to help them recall details about how a suspect looked. The artist produces sketches that coincide with the description, sometimes asking the witness if the sketch needs to be altered in anyway. Hand sketching was once the primary means of creating a facial composite, but modern computer techniques are becoming much more popular in the 21st century.
Computer software for facial compositing allows the witness to choose images from a database to match his or her memory of each feature on the suspect's face. In addition to narrowing down details like eye color or nose shape, the witness can also position the features on a face model and modify the sizes and relative positions of each feature. Identifying marks, such as scars, tattoos, or piercings may be added from databases or drawn onto the model.
A facial composite may be used in several different stages of criminal investigation and justice procedures. Law enforcement agents may use a composite image to create a “wanted” poster, that warns citizens of a potential criminal in the area and asks for any tips or sightings. Additionally, detectives or investigative personnel may rely on composites when tracking down people connected to a crime or following leads. In cases where a suspect's identity cannot be found or no prior photographs exist, a composite may be the only way to jar a witnesses memory about the suspect. Police may also use composites to compare sketches with databases of known criminals, to see if they can find a likely match.
Some studies have shown that facial composites are extremely prone to error. Unfortunately, in a heated event such as a criminal situation, even the keenest eyewitness may be too overwhelmed by adrenaline or fear to catch many details. Additionally, eyewitnesses may be prone to suggestion, and may become convinced of a detail that did not actually exist. Nevertheless, despite criticisms, facial composite images remain a widely-used tool in investigation and prosecution.