Obviously impressions of shoes or boots are more likely to be left at a crime scene than footprints. But if the surface is smooth enough and someone has bare feet, it is possible that footprint impressions or ridges on the bottom of the feet will be left behind much as fingerprints from the hands are.

Sometimes in television shows and movies they work out a suspect's height and weight from a footwear impression. However, this would be very difficult because the ground can be so different in each situation.

When examining a shoe or boot impression, a forensic officer looks first for any obvious characteristics. For example, is there enough tread to work out if the impression was left by a particular brand name shoe like Nike^® or Reebok^®?

Unfortunately a simple footprint in soil, grass or snow without any detail is of little more use than to suggest the path of travel that a person used, unless the size of the print can be worked out.

Shoe or boot impressions, if they have enough detail, are very important in investigations. If there is enough tread detail then it is likely that a cast of the footprint will be made so that it can be compared with the footwear worn by a suspect.

 Creating a plaster cast See a movie clip.

Make your own footprint cast

You will need the following materials:

• quick-setting plaster of Paris
• a container for mixing the plaster
• a soft brush
• material to use to make walls for a mould e.g. a cut-down ice-cream container or cardboard
• iceblock stick or old cloth.

Method:

1. Find a suitable area outside and make a shoe print. It should be moist sand or soil. If possible use an old shoe with characteristics that will make it easier to identify such as size, tread, design, wear spots or cuts.
2. Use cardboard or other materials to made a wall around the print. To use less plaster you could do this for only part of the print.
3. Pour some plaster of Paris into water and stir thoroughly. When the mixture is thick and creamy, immediately pour it into the mould, trying not to disturb the print. To strengthen the cast you could press some paddle-pop sticks or cloth into the top layer of wet plaster.
4. Leave the cast to dry, preferably overnight. Clean the container you mixed the plaster in.
5. When the cast is set hard, lift it carefully and wash gently under a tap. Use a soft brush to remove any dirt.
6. Collect the casts made by the class and try to match them to the shoes.

Most physical evidence involves a comparison between class characteristics and individual characteristics. Class characteristics are shared by a group of objects, for example many Reebok^® shoes have a similar tread design on the bottom.

Individual characteristics are particular to one person. The tread wears down at different rates and the sole gets particular marks and gouges. This is because of the differences in the way we walk, sometimes caused by personal injury, or particular size and weight. Accidental nicks, cuts and abrasions will occur to your shoes with time, and they will be different from any other shoes.

There is currently no database against which searches can be made for footprint impressions.

Compare footprints

Cast samples are analysed by comparing unique nicks, cuts or manufacturing marks visible on the impressions left by the sole of the shoe that would appear in corresponding places on the bottom of the shoe itself.

It is ideal to get the suspect's shoes for comparison as soon as possible so that further wear on the shoes does not create new nicks or cuts thereby altering the sole to the point where a comparison could not be made.

©The Crown in Right of Tasmania

The Department of Education would like to thank Tasmania Police, and in particular Tasmania Police Forensic Services, for their assistance in the making of these materials. Conditions of use (This item contains non-TLF content.)