Footwear, the Missed Evidence

There are many ways to secure footwear evidence in and around the crime scene. Once the area is secured and the crime scene is established the officer on the scene should make sure the entire scene is marked off using crime scene barricade tape, and no one should be permitted to enter until the crime scene investigator responds. In some cases where weather might have an effect on the footwear evidence, the first officer may place boxes, cones, etc. over the impressions until the crime scene investigator arrives. Remember, do not alter the evidence prior to any photographs.

Searching the Crime Scene

Always be aggressive and alert. Footwear evidence should be one of the first considerations at the crime scene. Once the scene has been made safe by the first officer(s) on the scene, it should then be secured for the crime scene investigator. The secured area should be marked off large enough to include any possible footwear impressions that my be leading to and away from the area. This officer securing the scene should pay careful attention not to leave his footwear impressions around the scene.

If the officer must enter the crime scene area, a military-type approach and exit should be used when at all possible. This type of approach consists of the individual stepping into his/her own footprints, therefore leaving only one set of additional footprints that can later be eliminated. A restricted route should be thoroughly searched for evidence. A planned search of the area should be conducted by the crime scene investigator on the scene. The area should be carefully photographed and documented as to where each footwear impression is found. This procedure should be done before any other search is performed. Once the footwear impressions have been located and marked as to their location, the crime scene investigator can come back later and complete the photographing, casting and collecting process.

Footwear evidence can be found at almost all crime scenes in two forms, impressions and prints. The techniques in recording such evidence may be different, but the search is basically the same. Always use a methodical and planned method of searching. Never blind search a crime scene. The only footwear evidence that is not found is that which is not searched for. Footwear evidence that is located out of doors should first be photographed and if three dimensional, cast. This will prevent any unfortunate destruction of the evidence while the crime scene investigator is inside. Each impression should be documented as to its position and surrounding areas. Remember, position can tell you direction of travel.

During an interior search, all surfaces where the suspect(s) may have entered or exited the scene should be carefully examined since most of the residue on the shoes from the outside surfaces may contain valuable impressions which are not easily seen under normal lighting conditions. To locate footwear impressions on indoor surfaces, the crime scene investigator should first attempt to darken the search area as much as possible. Then using a strong white light with a directional beam, cast the light over the surface at an oblique angle. Once the impressions are located, the collection and recovery process begins. Excellent devices with strong white light are the forensic light sources. They contain a narrow beam of white light that provides an excellent source of illumination when it is held at a low angle. Also this type of light is much stronger and brighter than normal flashlights.

Whether the impressions are indoors or out, they should be photographed, documented, lifted and/or cast. A photograph or lift differs from a cast in that it is a two-dimensional reproduction of a print, just as a fingerprint lift. A cast is a three-dimensional structure which can provide a positive reproduction of the footwear.

Remember that some impressions may only lift in partial and others do not lift at all, so always attempt to photograph the prints first. If the footwear is a visible print on an item that can be retrieved from the scene to the laboratory, then this should be the method of choice. It is much easier to work on the evidence under controlled conditions than to try collecting the footwear at the crime scene, but in some cases this is not possible. There are many lifting applications on the market that have been accepted for years. Adhesive paper or contact paper can be placed over the footwear print in dust or very light dirt.

This lifting method works by placing the adhesive paper or contact paper, adhesive side down, over the impression in dust or light dirt and smoothing over. This will allow the impressions to be transferred to the adhesive side of the paper. Once this is done the paper is then peeled off the impression and photographed. The paper can be treated with a mixture of 0.05 grams of crystal violet to 500 ml. of distilled water which stains the footwear impression, but produces a reversed image when collected. Once this is completed a piece of clear acetate is placed over the print in order to preserve it for impounding and later examination purposes.

Latent fingerprint powders and lifting tapes can be used on various surfaces for contrast and recovery.

Many of the chemicals used by latent fingerprint examiners can be used to enhance the footwear prints on a variety of items.