NCJ Number
80438
Journal
Journal of the Forensic Science Society Volume: 21 Issue: 3 Dated: (July 1981) Pages: 183-193
Date Published
1981
Length
11 pages
Annotation
The development of shoeprint and instrument-mark indexes at England's Metropolitan Police Laboratory is described, along with coding and retrieval methods and some examples of how the indexes have helped to solve crimes.
Abstract
To obtain more background information on footwear, all footwear coming into the General Chemistry Section of the Metropolitan Police Laboratory from April 1973 was photographed. This collection, which became known as the Footwear Index (not to be confused with the Shoeprint Index), now contains about 3,000 photographs of the soles, heels, and uppers of numerous types of footwear. Early in 1975, the collection of photographs of scenes-of-crime footwear marks was begun. For the next 2 years, the Shoeprint Index (SI) grew slowly but was accelerated in 1977 by the use of a full-size adhesive lifting film for shoeprints. SI data are stored on an Instem PDP-11 minicomputer. Once a search has been initiated, the computer prints out the records of all scenes having the designated parameters. The coding system deals only with footwear patterns, because the difficulties of coding general and specific wear characteristics in partial scene prints are formidable. In addition, the Instrument-Mark Index (IMI) was begun in 1977. The IMI is a collection of tip impressions from scenes where single-bladed tools have been used for forced entry. IMI details are entered on a punched card. A toolmark is coded primarily by the width of the tip of the tool. An important limitation of the IMI and SI is the change in footwear and levering tools over time. The greater the time between an offense and the comparison, the less the chance of a match. The indexes have been instrumental in solving many burglaries as well as a number of homicides. Photographic illustrations are provided.