Forensic Significance in Physical Evidence


Author: Anamika M J, National University of Advanced Legal Studies, Kochi


To understand the forensic significance of physical evidence in a crime we need to understand what forensic studies are. The application of natural sciences and physical sciences to matters of criminal and civil law is known as forensic sciences. Physical evidence is any object that can establish that a crime has been committed or that a crime has been committed or can provide a link between a crime and its victim or a crime and its perpetrator. There are different kinds of physical evidence. This can be classified as living and nonliving.


Non-living physical evidence includes glass pieces, soil and natural resources, paint, questioned documents, firearm and ammunition, powder residue, explosives, petroleum products, drugs, footprints, etc. Living physical evidence includes blood, organs, and other psychological fluids, fingerprints, hair and fibers. Glass pieces are very useful physical evidence in a crime scene. The size of the glass pieces from a crime scene helps to determine in case of a bullet hole to determine the speed and the projectile of the bullet. The cause of the breakage can also be known from these glass pieces which will link to the suspect in the crime. Soil or natural resources that can be obtained from the body or footwear of a victim in a crime scene will enable the investigation to understand the modes of Operandi of the suspect in certain cases. In most of these cases, these are considered to be circumstantial evidence with other materials to support. Paint evidence is mostly in the mode of a smear, chip, or dry which will help the investigator to recreate the instance in which the crime took place. These are most useful in the case of hit and run or car crashes. The handwriting are used to analyse in the case of a forged document. In case of a firing, a bullet may match to a cartridge thereby giving a clue to the weapon used to commit a crime. The presence of a disbursement powder residue indicates when and where a fire weapon was used. Since this powder is difficult to remove from skin and inanimate objects surrounding the person firing, it will help to locate the range of fire and the person firing it.

Tool, foot and tire marks are also important physical evidence which will help the forensic team in a crime scene. The tool marks on surfaces will help to find the tools used for committing the crime to certainty. The footprints are also of great importance since they will lead to the suspect in most cases. The size of the shoes of the suspect can be easily known from the prints, on further forensic analysis, these may also lead to understanding even the height in certain cases. Recently due to the use of drugs in different spheres, the drugs are manufactured illicitly in certain cases. When the drugs are obtained or in other words are captured from the suspects, a sample is collected and sent to the forensic lab to identify the group of the drug. The identification of the drug is done by various instruments with precision.


There are living physical evidence as well which will help in the investigation of a crime. As mentioned earlier blood, organs, physiological evidence, fingerprints, hair, fibre etc are some of the living evidence. Blood and body fluids will be analysed by biochemical methods to get any lead-in from the crime scene. The forensic team will analyse the crime scene and collect all the biological fluids obtained from the scene and also subjects them to DNA analysis to find whether the fluids obtained belong to the victim or the suspect. In certain situations, the marks of the fluid in case of blood will help in understanding what has happened in the crime scene. If there is a smirk of blood it may mean that the body has been dragged. Similarly, the organs of the victim are also subjected to biochemical analysis to find the presence of any questionable chemicals in the body of the victim thereby giving a lead on whether there were any unnatural reasons for the death. Fingerprints are also obtained from the crime scene by the forensic scientist, this will further enable them to identify the suspect who committed the crime. Earlier this was not very common but now with databases containing the fingerprints matching the fingerprints from the crime scene have become common. Hair and other body fibres mike the skin from the crime scene are also tested by the forensic scientist to bring a connection to the suspect and the crime scene. The bone fibres obtained from the crime scene will help to decide whether it belongs to an animal or human. The body fibres also help to obtain the DNA of the suspect if the fibres obtained from the body of the victim do not belong to the victim.


From the above discussion, we can understand the forensic significance of physical evidence in a crime. With the improvement in the forensic sciences over the years, forensic science has been used to prove crimes to a great extent, there are also certain situations in Indian courts where the forensic science is not considered valid. This is mainly because many of the laws or legislation which we follow in our country were framed during a period when forensic science was not evolved as it is now. Because of the same reason, the courts go by the traditional methods as modern ways are not considered.