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Impressions ASISTM Project Forensic Investigations.

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Presentation on theme: "Impressions ASISTM Project Forensic Investigations."— Presentation transcript:

1 Impressions ASISTM Project Forensic Investigations

2 Shoeprints The physical contact between the shoe and the surface results in a transfer of the individual characteristics of the shoe. Shoes prints are often used to prove that suspect was present at a crime scene.

3 3-dimensional impressions Footwear impressions are pressed into a soft surface such as mud. The impression is influenced by the weight of the person and the type of surface.

4 Casting a 3-dimensional impression Photography Paul Ricketts, 2006

5 Sports Shoes Photography Paul Ricketts, 2006

6 Boots Photography Paul Ricketts, 2006

7 Ladys shoes Photography Paul Ricketts, 2006

8 Using Alginate to make an impression 1 - alginate powder 2 - pour the alginate into a plastic bag3 - about 1/3 of a bag Photography Paul Ricketts, 2006

9 4- add water 5 - squish the powder and water 6 - thoroughly mix 7 - cut a small hole at a corner of the bag with scissors Photography Paul Ricketts, 2006

10 8 - squeeze out the alginate onto the impression. Work quickly as alginate dries very fast. 9 - carefully pat into place 10 - the alginate changes colour when dry - carefully lift from the impression Photography Paul Ricketts, 2006

11 10 - wash away as much dirt as possible The finished impression Pict of finished impression - to do Photography Paul Ricketts, 2006

12 2-dimensional impressions 2-dimensional impressions occur when an image of the print is left on the surface. Some 2-dimensional impressions are highly visible – muddy footprints on a cleaned floor – while others are latent or invisible.

13 2-dimensional impression: Blood Photography Paul Ricketts, 2006

14 Latent 2-dimensional impression: luminol

15 Other impressions Casts can be taken of the impressions of other objects. Eg, tyre tread

16 Tyre tread Photography Paul Ricketts, 2006

17 Tyre tread on ground Photography Paul Ricketts, 2006

18 References Images All photography by Paul Ricketts, DUIT Multimedia, the University of Western Australia. J. Baines is the model for the sequence of photographs showing taking a shoeprint impression using Alginate. Shoes supplied by J. Dook. Graphic design of slides by Trevor Hutchison, DUIT Multimedia, the University of Western Australia.


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