Monday, February 19, 2007
Cinderella analysis: Forensic Foot Prints
In the UK there is now a forensic footwear intelligence database which contains images of thousands of types of shoes, to help track down criminals. Under new laws, suspects who are arrested but not yet charged can have a shoe profile recorded. This involves photographing the shoe and making an ink impression of the sole. Criminals leave their footprints at approx. 40% of crime scenes, which provides the second-biggest evidence type behind blood and DNA, according to forensic experts. Like fingerprints, hair, blood or fibres, footprints can provide vital clues. Most are not clean marks in fresh mud, but more subtle impressions that cannot be seen with the naked eye may be enhanced using UV light. It is even possible to recover a shoe impression from a carpet or a dead body. Although unique footmarks can confirm a suspect had visited the crime scene, it would almost always be used with other evidence. Footwear prints and marks from crime scenes and information from manufacturers will be retained on the database and updated, daily. This information would include the type of shoe, colour, branding and marks. It will also hold data on thousands of suspects and about shoe marks found at all crime scenes across the country. Software allows quick comparisons to be made between the database sample, and a cast or photograph of the footwear mark from the crime scene. The Cinderella Analysis database helps forensic experts link shoes to the crime and the individual when a suspect is identified. Police hope the new footwear database will allow them to link the scenes of unsolved crimes to suspects more quickly, and link crimes carried out by the same person. This system is similar to the DNA database of genetic samples which was introduced in 1995 and now contains millions of profiles. The Footwear Intelligence Tool (FIT) was developed by the Forensic Science Service and will automatically search for matches between shoe prints and crimes, in much the same way as the United Kingdom's DNA database cross-references DNA samples from those who have been arrested to samples linked to crimes. This is thought to be the world's first national database of shoe imprints. The system has already been used successfully to track down suspected bombers and in major criminal cases.