A crime scene is a goldmine for collecting evidences which can be very helpful in identifying the suspect. One of such evidences is footprints which are often found in crime scenes and marked as a vital evidence. To quote Paul and Kirk (1974),
“Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as silent evidence against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects – all these and more bear mute witness against him…..Physical evidence cannot be wrong; it cannot perjure itself; it cannot be wholly absent. Only its interpretation can err. Only human failure to find it, study and understand it, can diminish its value”[1]
In 1915, a Footprint Section was established under the CID, Government of Bengal, which helped the police to identify suspects by collecting and examining footprints from the crime scene.[2]Footprints cough up several information like size of foot, presence or absence of shoe, sex of the person, the direction of movement, manner of stepping, which can predict ample information of the concerned person. Hence, collecting footprints on a crime scene should be an investigator’s prime priority as they can play a vital role in legal proceedings and can be quite helpful in solving a case.
Though criminals are smart enough to use gloves or any kind of protection over their hands to avoid fingerprints all around the crime scene, they make little attempts to conceal their footwear. So, it is reasonably assumed that they would leave footwear traces in the crime scene. Thus, this type of evidence should not be overlooked and should be examined by a footwear expert. Basically, the investigators try to identify the built and model of the shoe which made the impression. They could either compare it with other evidence or from the visuals of the impression they could focus heavily on brand and logo marks or pattern marks on the sole of the shoe. The detailed procedure along with the various types of footprints and the methods of collecting them are further discussed in this article.
Types of foot prints
Footwear evidence can be found in two forms – prints and impressions. A print is on made on a solid surface by, for example, dust particles. Whereas an impression is generally three-dimensional in nature like made in mud or any supple material. Footprints found, whether indoors or outdoors, are categorized into the following –
1. Visible or patent print –
When a person’s shoe soles or feet are contaminated by a substance which is then imprinted on a dry floor or any clean surface, a visible or patent print is captured. As it is visible to the naked eye, it is quite helpful in investigations.
2. Impressed or Plastic prints –
When footprints are captured on soft surfaces or any supple or impressionable surfaces like mud or clay surface, snow, wet sand they are termed as impressed prints. These are photographed and then cast to be used in further investigation procedures.
3. Latent print –
These are footprints which are not visible to the naked eye and are generally found on smooth surfaces. They can be located and collected with powders and chemicals. The oblique lighting technique is also used to find such prints. Powders are used to create contrast so that it eases its visibility while photographing. They are then recovered by using lifting tapes.
Methods of recording footwear impressions
The fundamental methods of recording foot impressions are as following –
1. Photography –
A two-dimensional evidence where the impression is photographed and captured for record. Prints which cannot be readily lifted are photographed with Polaroid 665 black and white film loaded in a Polaroid CU-5 camera with detachable flash.[3]
2. Casting –
A three-dimensional evidence in which the impression of the foot is reproduced. For instance, one method of casting is done by plaster. A ruler is first used to measure the size of the impression. Hair spray is sprayed on the footprint to prevent the dirt from crumbling and sticking to the plaster. Plaster is then poured on the impression and allowed to set. Once the plaster dries up, the plaster is flipped and the cast created to be examined further.[4]
3. Lifting –
This method is used when a foot impression is a visible print on an item. If the impression is in dust, an adhesive paper is used with its adhesive side downwards to transfer the print on the adhesive paper. The paper is then peeled off the impression and photographed. The print collected is then stained by treating the paper with a solution of 0.05 grams of crystal violet into 500 ml of distilled water. After staining, the print is preserved to be examined later by placing a piece of clear acetate over it.[5] Footprints or shoeprints which cannot be picked up are collected by the following techniques –
- Adhesive lifter – A heavy coating of adhesive is used to lift the imprint from hard surfaces like tile, metal surfaces, hardwood floors and are used along with fingerprint powders.
- Gelatin lifter – A flexible rubber sheet is used which has a low-adhesive gelatin layer on one side which is used to lift prints from a variety of surfaces like rough, irregular, porous and curved surfaces.
- Electrostatic dust-print lifting device – it is a device which charges particles electrostatically within dust, which are then attracted and bonded to a lifting film. Thus, it is useful in collecting dusty residue from any surface.
Conclusion
It is unanimously agreed that medical and forensic evidence plays a crucial role as a stepping stone in finding the suspect of the crime. As footprints and fingerprints are the most common and abundant form of evidence found at a crime scene and copious data can be procured from them, it becomes quintessential that they are uncontaminated until recorded and collected from the crime scene. The infamously famous case of Aarushi Talwar[6] which provides evident proof of a botched investigation by the police where they failed to secure the crime scene immediately.
Further, evidence on the crime scene was mishandled and tampered with, rendering the case unsolvable. This case is a glaring lesson in the face of justice and thus, it is pertinent that the evidence, in any form, has to be handled cautiously with proper methods and measures as their importance can completely get nullified if they are tampered with or mishandled, complicating the investigation process, ultimately delaying justice to the deserved.
[1]http://sifs.in/blog/crime-scene-and-evidences-encountered/
[2]Manish Sati, “Evidentiary value of Forensic Report in Indian Courts” (2016) https://scholarticles.wordpress.com/2016/02/11/ms1/.
[3]https://www.crime-scene-investigator.net/evidenc3.html.
[4]https://www.crimescene.com/pooch-evidence/5364-young-footprint.
[5]http://science.howstuffworks.com/impression-evidence2.htm.
[6]https://thewire.in/government/aarushi-talwar-criminal-justice-system-reform.
This Article written by Venkata Moksha, Student of National University of Study and Research in Law, Ranchi.
Also Read – Forensic Significance of Physical Evidences in Crime Scene Investigation
