Question: How many ways do you know of getting a fingerprint and shoe print

Mark Hill answered on 16 Mar 2011:

Hello Edwardjenner,

When I examine something for fingerprints, footprints, or any marks, clothing marks or ‘cleaning marks’, I always examine the object, whether a vehicle, or something else, using a special crime scene examination lamp, called a SocLamp, or a Crimelight (other makes of lamp are available). They are designed to give a low level clean light, without any shadows or ‘cast’. The light is shone at a low angle onto surfaces, to try and locate marks.

Let us talk about finger and palm prints, on a car bonnet, for an example.

Once I have identified a mark, if it is visible without being developed (I will come to that in a minute) then I will photograph it, with a scale bar and marker alongside, to give its size, location on the panel and its direction. This is all important in working out which way a pedestrian was walking when they were hit by a vehicle. All forensic work is to the same very important rule – non-destructive techniques for testing and recovering, before destructive techniques, so, photos first.

If the mark cannot be photographed clearly, then I may use a very fine metal flake, or dark oxide powder and a fine brush, synthetic (such as a Zephyr). In a very gentle manner I will lightly develop the mark, barely touching it, but such that the powder sticks to the sweat and sebaceous fats that make up the print. Once this is developed, I can then hopefully photograph it and lift it, with a clear sticky tape, onto a piece of Cobex (stiff clear plastic).

Sometimes marks, especially shoe marks, can be lifted with a black coloured gelatine sheet, which will lift the very fine marks of a print, including damage marks on the soles of worn and old shoes. These marks can be as conclusive in evidence as fingerprints.

Another technique that I can use is with an electronic device and a sheet of paper with an electrostatically charged coating. The device is known for short as ESLA, but stands for electrostatic lifting apparatus. This causes the film to ‘lift a very accurate copy of the mark, for later comparison against detailed catalogues of shoe sole patterns.

The other obvious instance is with a shoe print (or other print) in a soft substrate, such as mud. It can also be used for tyre prints as well, which have the same potential for identification as worn shoes, with wear patterns and damage marks. We use a type of plaster cast, or a resin, such as Isofix. We make a mould around the mark, mix up the plaster, or resin, and pour it onto the print. Then we have a good copy once it is set.

A couple of other techniques are for prints on paper, which generally cannot be seen. A substance (rather poisonous) called ninhydrin, is applied to the paper, in gaseous form, in a fume cupboard. This sets and develops sweat prints.

A nother way is using Superglue, or cyanoacrylate, which is varourised, in a sealed environment. This sets on prints in a similar manner. This can also be used on large objects, such a s cars, where a simple SOCO tent is put over the vehicle. The process is known as ‘superfume’ and is very effective, even if it does ruin the car paint!

These are the main techniques that I use. There others, but these seem to be in common use with all crime scene investigators. You may see some of these techniques on CSI and in NCIS, but they don’t generally use them correctly and their scene examination techniques, cross-contamination is terrible.

I hope that these answers help you.

Thank you for a good question.

Mark.