In a scientific investigation, physical evidence plays a key role in linking
the suspect and the victim to every alternative or to the crime scene. Evidence
is visible, collected at the scene and sent to a laboratory for scientific
examination according to the investigator's needs.
As all crime scenes are naturally different then almost anything can be
considered as physical evidence depending on the type of crime and the
circumstances under which the crime took place. According to section 1571 of the
Indian Cr. P. C., the crime scene is a very rich source of various kinds of
evidence. It must be thoroughly searched.
What Is Physical Evidence?
Physical evidence refers to any material objects that may be present at the
scene, at the victims, or found on the suspect. Tracing evidence refers to the
physical evidence available in small but measurable amounts, such as hair
follicles, strands, or skin cells. The evidence gathered at the scene is
analysed and the results used in a criminal investigation to prove or disprove
the facts of the case.
Physical evidence can be considered as:
- Corroborative evidence, often confirming or supporting criminal theory,
- Circumstantial evidence, which indirectly gives a certain conclusion
They are also called real evidence and are indirect types of evidence, which
include tangible subjects such as hair, strands, hidden finger and foot traces
and other biological and chemical elements.
Locard's Exchange Principle
'Every Contact leaves a Trace'
The importance of tracking forensic evidence was first recognized by Edmund
Locard in 1910. He was the director of the first existing criminal laboratory,
located in Lyon, France. Locard's Exchange Principle states that "with the
affiliation between the 2, there'll be associate exchange". as an example,
burglars can leave traces of their presence and can follow the trail They could
leave hair on their bodies or strands on their garments back and should take
carpet strips away.
Types Of Physical Evidence
Paint: physical and chemical analysis of paint evidence (chips or residues) may
indicate its class, such as car paint, house paint, nail paint, etc.
Proof of paint can also show individual characteristics if the investigator
is able to find similarities between two samples, such as colour, number of
layers, chemical composition, or actual similarity between the edges of two
paint chips, one from a tool and one from crime scene.
Most of the evidence for painting comes from crimes involving hit-and-run
cases. With a controlled sample comparison sample, the paint can be compared
to a car with almost 100% certainty3.
Glass Pieces: Windows or glass windows, particles, or fragments found or transferred to a
person or object involved in crime may be strong evidence.
Such evidence, whether broken by a bullet or otherwise, helps to determine
its colour, features, brightness, density, chemical composition, and
The test results provide clues about the crime and help investigators to
link evidence with the suspect or other object used in the crime, such as
matching glass from the crime scene to the suspect's car light.
In addition, a lower surface is usually found for fingerprints and / or
blood to be present in broken glass 4.
Explosives And Petroleum Products: Explosive and petroleum products are equipment that contains explosive
charge, as well as all substances released from an explosion or heat source
that is likely to contain residual petroleum material. The presence of these
elements becomes an important factor in determining where a fire or
explosion originated and where it continued.
Another feature of petroleum products is related to adultery.
For which appropriate collection and analysis helps determine the chemical
composition of such materials that can help identify the origin and users of
the material. Traces of explosives found on clothing, skin, hair, or other
items of the suspect may be likened to explosives from a crime scene.
Ballisitcs: Guns, as well as ammunition or incomplete ammunition, are often the most
important evidence in any shooting investigation. In fact, it is almost
impossible to obtain a conviction for shooting cases without the discovery
of such evidence. If anyone is accompanied by a suspected weapon, a bullet
wound, or a case of a broken cartridge can be compared to a weapon and a
fingerprint can be compared to a finger. The characteristics of ammunition,
firearms and ammunition are examined to determine the similarities between
the suspects and the evidence available at the scene.
Chemical tests may reveal gunshot wounds (GSR) on the hands, face, or
clothing of the victim or suspect to show how close the person was to the
Shooting at a barrel of a gun causes separate canals, bends, and scratches
on the bullets, which can be likened to a shotgun.
Police can search the National Integrated Ballistics Identification System (NIBIS)
website to compare symbols from bullets, cartridge cases, and gun shells
with ball proof 5.
Fracture Matches: When an object is broken, torn, or cut, two distinct edges are formed,
These ends can be compared with the naked eye or microscope to see if they
fit together, indicating that they may have been part of the same object at
the same time.
Investigators may compare a piece of tape pieces, pieces of glass, pieces of
paint, pieces of car accident, paper bag, etc. to find the same potential
Soil And Natural Resources: Any material (clothing or footwear) that contains soil, wood, natural
resources such as minerals or other organic matter can help to link a person
or thing to a particular place (for example, sandals embedded in a shoe and
the vault insertion found in a garment). Many such samples do not prove to
be identical, but it is possible by the presence of a rare object. Such
types of evidence are often regarded as rare, but they are useful in
supporting other evidence in a case6.
Questioned Documents: Any document in question, whether handwritten or handwritten, is sent to the
laboratory for authenticity and source. These types of analysis are widely
used for ransom notes, suicide notes, death threats, and fraud. When
typewriters were used, it was easy to compare the typewriters with the
products they produce. With the advent of inkjets and laser printers,
comparing printed texts is almost impossible.
The exception may be if the document can be printed in an unusual font or
with a rare ink type. Since reducing the use of typewriters, document
analysis is now more focused on handwritten texts. Although each manuscript
is the first one, no one duplicates the same text twice. The designers are
smart and clever while trying to reproduce the signatures. For these
reasons, handwriting analysis does not usually provide 100% similarity.
Summarizing other types of work in document fragmentation include fraudulent
acquisition and replacement; handwriting comparisons; reconstruction of
damaged documents; identify and compare printers, typewriters or copies used
to produce text. Inspectors will analyse a ransom note or other document to
obtain clues to link it to the crime scene or to a specific suspect. they
will analyse the type of paper used, the printing method or handwriting
method, and the type of ink7.
Impression Evidence: 3D impressions naturally include tool marks, tire marks, shoe or footprints,
compression of lost or soft soil, and all other types of track ideas, and
markings on the skin or on various types of food 8.
Shoe stamps and tire tracks:
- The resulting evidence may be captured, taped, or cast to match the
suspect's shoes or tires.
- Investigators will examine the evidence to identify the type of shoe or
tire based on its tread pattern and other visible features to provide clues
to the case.
- Shoes and tires will also show patterns of wear after being used for
some time as well as other features (scratches, nicks, cuts) that can be
used to match the evidence with certain items. for example, shoe stamps can
be compared to a suspect based on the way the shoes are worn because of the
person's style of walking 9.
- Each of the 32 teeth in humans is different due to age and aging.
- Impressions and images of the bite marks left on the victim, attacker,
or other object at the scene can often be associated with dental records10.
- Small nicks and chips form on the edges of the tool as it is used, which
can be used to identify similarities between the evidence and the suspects.
- Tools may also pick up blood stains or other items that can be tested or
have raised fingerprints that can be raised11.
Drugs: Drugs are substances that violate the laws governing the sale,
production, distribution, and use of drugs or chemicals and that need to be
caught. A large number of perpetrators of some forms of crime are involved with
drugs. Drug production is big business. With the advancement of technological
advances and the easy availability of chemicals, it has become much easier to
manufacture illegal drugs and it has become increasingly difficult to catch
When suspected drugs are found at the scene or in the body, samples are packed
and sent to a forensic science laboratory for analysis. Preliminary or spot
tests to find out who the drug is. Further verification tests will determine the
strength of the drug and its components. The identification of drugs was
completed with the use of various instruments. Although such equipment is
expensive and requires frequent repairs, the results of such tests are
Blood, Organ, And Other Physiological Fluids: Blood and body fluids (semen
and saliva) will be tested for biochemistry and other analyses to determine your
identity and origin and then your identity. By checking the amount, colour, and
distribution of such liquids, the investigator may be able to predict several
times what happened at the scene. A smear may indicate an attempt to clean or
drag the body.
An accident occurs when blood flies at an angle and hits an object. The
'exclamation mark' feature indicates where the movement is.
After careful collection, almost every type of organ or living organism will
undergo blood transfusions and DNA analysis.
Toxicology tests may also identify the possible presence of a drug, alcohol, or
poison Blood type, used to exonerate innocent people and identify potential
suspects or victims, is still a useful tool. However, recent advances in
techniques, tools, and collection processes have increased DNA testing into more
Fingerprints: It is generally known that when a person touches a subject
with his or her hands (according to Locard's exchange system) that the printing
fingers are left behind. Such prints are called latent prints as they are
invisible to the naked eye. The challenge for the palaeontologist is to develop
to identify, these hidden documents to find their owners.
In the past, matching
these prints required a narrow field for the suspects, but with the use of
computers and a large database, identifying the suspect's documents has become
Investigators also identified unique features of the ridge on fingerprints that
could be used to identify a suspect or a victim.
AFIS (Automatic Fingerprint Identification System) is a website used by
investigators at local, regional, and national levels to search similar to the
fingerprints found at the scene.
Hairs And Fibers: hair and strands may be transferred from the suspect or
the suspect's clothes to the victims and vice versa. For example, a suspect
might take strips of carpet from his shoes or leave his hair behind in a crime
Hair can be examined to determine its origin, such as a human or an animal. Root
hairs may be complete without DNA testing.
Fibres are used to make clothes, carpets, furniture, beds, and bedding. It may
be natural fibres from plants or animals or man-made synthetic fibres14.
Wounds:Wounds can often be likened to weapons or Armor on a weapon. Investigators may
also be able to determine the size, shape, and length of a weapon. Wound
analysis may provide indications of the victim's injury, the characteristics of
the suspect (left hand, right, height, etc.), and the position of the victim and
the suspect at the time of the incident15.
Nitish Kumar Murder Case 16
In this case, it was very difficult to find the person guilty because only a
small part of the tent with his finger was left unburned. But with the help of
forensic science a DNA test was performed and assisted in identifying and
identifying the body by associating DNA with parents. This also enabled the
Delhi High Court to identify the suspects.
Sushil Mandal Vs The State 17
In this case, the father of the deceased boy is an applicant who has challenged
genetic results. A dead boy fell on top of a teenage girl who fell in love with
a girl from his school. Thus, the parents of both families were asked by the
school principal to examine the children. A few days later, the boy was found
missing, and a week later, the body was found in a decaying lake, which is
unbelievable. The petitioner could not identify the body, and the clothes were
not there to identify him as his son. He filed a habeas corpus application in
the Supreme Court against the girl's father and asked the Supreme Court to
direct an investigation into the CBI (Central Bureau of Investigation).
The geneticist's DNA and DNA of the deceased were then combined with the
applicant and his wife. There was also a skull superimposition test. The autopsy
also found contact between the deceased and the body found. But the petitioner
could not accept the truth. The truth emerged only when scientific experiments
were performed. The Supreme Court relied on scientific experiments and the case
Physical evidence can be a very important part of a criminal investigation.
However, for that to happen, evidence must be gathered and analysed. In the case
of a serious crime, all possible physical evidence must be gathered. Since other
evidence is evidence of tracking, this means a complete search, or "finger"
search of the scene.
The way search is conducted depends largely on the context of the incident, but
it will usually focus on a body-like area, then work outside or inside around.
In some cases, investigators will work on a grid design to ensure that nothing
is missing. The body itself is an important source of physical evidence and a
search of the strings or fingerprints will always be done before you are taken
to the morgue.
If physical evidence will be allowed in court, then a series of stocks should be
proved. That is, each person in charge of the evidence from their collection to
their appearance in court must have already signed it. Therefore, the court
knows who was in charge at each stage of the trip. Safety measures will be taken
to prevent any contamination.
If the person presents at the scene, then examined the suspect, he or she may
pass on evidence such as a piece of cloth at the scene to the suspect. Ideally,
the same officer would not switch between the scene and the suspect's residence.
If they do, due to limitations on the number of staff investigating the crime,
they should be removed from the area and be able to prove to the court that they
have done so.
Once the physical evidence has reached the forensic laboratory, it should be
kept under safe conditions. It should be noted that the items do not decay under
their storage conditions in the event of a long period before any criminal
proceedings are instituted. There are several different laboratory techniques
that can assist in analysing and identifying the source of physical evidence.
For example, visual micro spectrophotometry is useful in identifying the
chemical nature of pieces of paint or fabrics.
Usually, these will be compared with the most reliable samples or those taken
from the suspect. It may not be all evidence that proves useful in solving a
crime, but it is better for investigators to gather more physical evidence than
less. If they know how to keep it safe and the best way to explain it in the
context of other evidence, tangible evidence can be a powerful guide to the
circumstances and the perpetrator18.
With the advancement of forensic science in recent years, forensic science has
been used to justify crime on a large scale, and there are cases in Indian
courts where forensic science can be considered illegal. This is because most of
the laws or regulations that we follow in our country were established at a time
when forensic science was not as consistent as it is now. For the same reason,
the courts are moving in the traditional way as modern methods can be
The main advantage of using the forensic science is to produce evidence to
obtain a fair trial. This is so that the real criminal may be punished and not
innocent. Legal evidence has always been helpful in many cases to identify the
real culprit and then the court will punish him.
Forensic evidence is far more important than the general evidence presented in
court. Although there are sometimes errors in the evidence, which is very rare.
More and more professionals should be noted for always providing relevant
information and evidence about the case, and that is why the case can be
resolved that way. There could be more progress in the country by making our
forensic science grow. This can create stricter rules for punishing the
- Procedure for investigation preliminary inquiry
- Nitish Kumar v State of Bihar 2019
- Sushil Mandal v The State Represented 2014