• forensic science;
  • footwear impression;
  • shoe impression;
  • individual characteristics;
  • dust print;
  • indented;
  • Electrostatic Detection Apparatus2;
  • Electrostatic Dust Print Lifter

ABSTRACT: The Electrostatic Dust Print Lifter (EDPL) and the Electrostatic Detection Apparatus2 (ESDA2) were compared to determine if both processes could be used to develop footwear impressions of the same or similar quality and in what order they should be used to develop the highest quality footwear impression. The sensitivity of each technique was also evaluated. The quality of the footwear impressions developed was determined by comparing 25 individual characteristics present on the known shoe to the footwear impressions developed using each technique. The footwear impressions were made by stepping on paper placed over several different surfaces, which included: linoleum, industrial Berber carpet, nylon carpet placed over a ⅜-in. pad, ceramic tile, cardboard, 1-in. foam, 4-in. foam, cement, asphalt, grass, and mulch. Each of the papers placed on these surfaces was developed using the EDPL before the ESDA2 and vice versa. The sensitivity test for the ESDA2 was conducted by processing 10 sheets of stacked paper that were stepped on with the known shoe, beginning with the top sheet. The sensitivity test for the EDPL was conducted by processing 10 sheets of paper stepped on with the known shoe in succession. This study determined the footwear impressions developed using the EDPL were of better comparative value than impressions developed with the ESDA2. On average, 72.4% of the individual characteristics from the known impression were identified on images developed when the EDPL was used first compared with an average of 38.9% when the ESDA2 was used first. Therefore, if only one technique is used, the EDPL should be chosen. The sensitivity test determined the ESDA2 develops high-quality footwear impressions on only the top sheet of paper. No footwear impressions were developed on any sheets under the top sheet of paper. The sensitivity test also determined the EDPL results increase in quality as the amount of dust residue decreases on the surface.