Crime in some form or the other has existed since the beginning of human race. As Science and technology developed, criminal and the concept of crime has undergone a tremendous change. Due to this criminal used their intelligence to use technology to their benefit and the police investigators find it difficult to depend on their conventional style of investigation, interrogation, and surveillance to detect crime.

The traditional way of detecting crime by using torturous methods is no longer applicable in the current scenario. Under this circumstance, the police investigators also depend on science to carry out their investigations. This is where Forensic Science has come to their rescue and acts as a powerful weapon in the hands of judiciary and law enforcement departments.

'Forensic' is a word derived from the Latin term 'Forensic' meaning belonging to court of Justice or public discussion and debate.' 'Forensic Science', means the science which is used in the court of Justice'. Forensic Science is a scientific discipline that deals with the recognition, individualization, identification, and evaluation of physical evidence by applying the procedure of natural sciences used for the purpose of administration of criminal justice.

Forensic science includes all branches of science like medicine, surgery, biology, photography, physics, and Chemistry. However, in later years it has developed its own branches like, DNA Fingerprinting, Entomology, anthropology, ballistics, Hairs and Fibres, Fingerprint Odontology, Pathology, questioned documents and toxicology.

Currently, Forensic engineering, forensic neuropathology and forensic accounting and fraud auditing are the other branches added to it. Secondly Polygraph is another lie detection test which is an interaction between the mind and body. In this method various components and sensors of a polygraph machine are attached to the body of the person who is cross-examined by the expert.5 Any changes in the pulse rate, respiration rate, blood pressure, and electrical resistance at the skin denotes conscious effort made by the subject to hold back information.

Brain Mapping is the third type of lie detection test in which the test sensors are attached to the head of the person. Later, some pictures or shown or is made to hear some sounds through the connected computer. Any kind of electrical activity or response shown is observed by the sensors and registers P300 waves. Such response happens when the person is connected with the picture shown or sound heard.

This clearly shows that the individual is related in some way or the other with the incident. DNA Fingerprinting is the fourth type of test which is the biological blueprint of life. In our country this method is considered to be a vital method in the field of forensic science. This is a more comprehensive scientific examination than any other method or branch of forensic science.

DNA Fingerprinting can be used to detect any type of crime like is murders, hit and run cases, assaults, dacoities, encounter, rape and other body offences against anybody. This can be done with a variety of materials like hair roots, saliva blood, semen, etc. The criminal unconsciously leaves any of these materials at the spot. Each and every living cell of our body has a DNA which helps to trace the person.

Main Functional Elements of Forensic Science in Crime Investigation
The prime functional components of forensic science are as follows:

1. Corpus delicti:
   The cause of death could be homicidal, suicidal, accidental, or natural. Forensic Science ascertains the cause and nature of death to establish whether the death was homicidal or non-homicidal. It can also differentiate a fake incident from the real one.
    
2. Modus Operandi:
   The inspection of the corpus deliciti, crime scene, evidentiary clues, and the surrounding condition indicates the possible modus operandi.
    
3. Criminal identity:
   The identity of the offender could be discovered with the help of many clues that include mobile phone records, personal details like SMS, emails, transactions which provide some relevant information about his participation in the crime. The culprit may also leave some traces behind like footprints, fingerprints, hair, blood drops, saliva, semen, or other body fluids on the victim's body or on weapons at the place of crime. In certain circumstances, a series of chain is created all of which when linked together connects a suspect with the crime.
    
4. Victim identity:
   Forensic Science through a detailed study of personal clues helps to find out the unknown deceased person, any mutilated dead body, or any skeletal remains. There are other clues as well that help in the identification of the victim's body, but DNA profiling and fingerprints give major hints in this respect.
    
5. Forensic Scientists:
   Forensic scientists assist the criminal justice system in many ways. They apply the principles of the physical or natural sciences for the analysis of distinct evidence which can prove the guilt or innocence of the suspect during investigation and trials. A forensic scientist takes the lead of investigation; he distinguishes the real crime scene from the fake one. The sequence of events relating to any incident is established by him that aids in further investigation.

Forensic Evidence and its Analysis in Crime Investigation
Evidence can be in any form of data or information that is presented in the court which could possibly prove the guilt or innocence of whosoever is the suspect. Forensic science played a vital role by introducing forensic evidence in the field of law. Forensic evidence is obtained by using scientific methods and later called on to be produced in the court. It acts as a proof for the offence or defence and also determines the extent of participation of any person in crime.

Forensic evidence is collected, processed, analyzed, interpreted, and presented to provide information regarding the corpus delicti and revelation about the modus operandi. It can be utilized to link crimes that are presumed to be related to one another.

This linking of crimes helps the police authorities to narrow the range of possible suspects and to establish patterns of crime that helps in the identification and prosecution of the accused. Some of the common Forensic Evidence are classified as physical evidence, transfer evidence, trace evidence, pattern evidence and transient evidence.

• Physical evidence is usually found at crime scenes and contributes in understanding the case by perceiving these evidences. Example - fingerprints, footprints, handprints, cut marks, tool marks and such other marks.
• Transfer evidence refers to that evidence which is exchanged as a result of contact between two objects.
• Trace evidence exists in small traces or are very minute in size that usually goes unnoticed and can be transferred or exchanged between two surfaces, example - dust, soil, hair, fiber and other materials.
• Pattern evidence includes finger impressions, foot impressions, gunshot residue, and other impressions that are later interpreted to discover the evidence.
• Transient evidence is temporary evidence and can be easily altered or lost that must be recorded at the crime spot as soon as possible, which includes odors, temperature, and certain imprints that do not last for a longer period.

Statement of problems associated with Forensic Analysis and Services
As nothing is perfect in this world, we cannot refuse to acknowledge the fact that science is not completely free from certain flaws and faults. Unfortunately, the disciplines and methods used in forensic science have to go through several shortcomings. Forensic analysis is not an effortless task to achieve it has to deal with several obstructions and challenges. Numerous defects have put the services of forensic at stake and therefore have shaken its scientific foundation.

Some of the common problems that are faced quite often are mentioned below:

• � A surprisingly high rate of errors in the laboratories is one of the emerging problems which includes cross contamination and mix up of DNA samples, these errors seem to be persistent in forensic labs.
• � The results of the test conducted are often falsified by dishonest DNA Analysts. They manipulate the test outcome to cover up errors.
• � Scientific analysis is a tedious task and consumes a lot of time and as a result the judgment is delayed. The interpretation of analysis varies from person to person which may cause difference in opinions.
• � Analysis needs to be precise and accurate as much as possible and if not might show ambiguous figures.
• � In reality evidence is not always easily available.
• � Forensic evidence can be manipulated, altered, or moderated which may end up in unjust verdict.
• � Forensic analysis can be averted by strong influences (political or financial factors).
• � There is no specific manner to validate the results of experiment, it requires broad knowledge and deep study.
• � Last but not the least any kind of inefficiency and misinterpretation can mislead the scientific analysis.

Dimensions Of Forensic Science Tests

• Lie Detection Tests
  During the early years of 20th century Psychosomatic disorders received a great deal of study by psychologists, psychiatrists, and physiologists. What is meant by this phrase 'Psychosomatic disorders' is simply that certain disorders at the body, or some, may be covered by emotions. The modern lie detector technique is also based on the principle of psycho so matic interaction which means that emotional experiences, as felt by the individual, causing certain type of psychological disturbance are always found to go together and that the evidence for the occurrence of one can be used as evidence for the occurrence of the other.
   
• Narco-analysis test
  The term 'narco-analysis' derived from the Greek word "Narke" means 'anaesthesia or torpor' and is used to describe a diagnostic and psychotherapeutic technique that uses psychotropic drugs, particularly barbiturates, which act as central nervous system depressants, and by virtue of this they produce a wide spectrum of effects, from mild sedition to anaesthesia. It is also known as drug hypnosis or truth serum or a combination of hypnosis and narcosis.

Polygraph Test
It is a common knowledge that when a person lies, he produces observable physical symptoms, such as, rushing of blood to the face, twitching of lips, movement of toes, movement of the 'Adam's apple' etc.

In modern times the scientists have designed instruments that can record the truth or deception. A volcano has emerged in the age of old laws of crime detection along with established laws of evidence and criminal jurisprudence with the introduction of new techniques of lie detection. The polygraph works on the principle that change in the person's perception or consciously held feelings produces a defense reaction in the form of psychological changes i.e., in the pulse rate, blood pressure, respiration rate and electrical resistance at the skin known as G.S.R. (Galvanic Skin Response).

The polygraph is an examination, which is based on the assumption that there is an interaction between the mind and body and is conducted by various components or the sensors of a polygraph machine, which are attached to the body of the person who is interrogated by the expert. Polygraph tests are conducted for various reasons. In USA and Japan, besides using it to arrest in crime investigation, it is used for pre-employment test on prospective employees.

Brain Mapping
When the brain recognizes a person or a sound it generates a particular type of electrical wave and this wave is called P300 or Brain Mapping. In modern times, it is recognized as a reliable forensic tool in investigation of facts by the government.46

This test was developed and patented in 1995 by neurologist Dr. Lawrence A. Farwell, Director and Chief Scientist, 'Brain Wave Fingerprinting'; the accused is first interviewed and interrogated to find out whether he is concealing any information.

Such tests are generally resorted in cases of white-collar crimes or in heinous crimes and attempts to correlate changes in the cognitive evoked potential with the patient's clinical changes.

Brain Fingerprinting

Dr. Lawrence Farwell's 'Brain Fingerprinting' technique has attracted considerable publicity but has not been the subject of any rigorous independent study. Besides this preliminary doubt, an important objection is centred on the inherent difficulty of designing the appropriate 'probes' for the test.

Even if the 'probes' are prepared by the examiner who is thoroughly aware with all aspects of the facts being investigated, there is always a chance that a subject may have had prior exposure to the material probes. In case of such prior exposure, even if the subject is found to be familiar with the probes, the same will be meaningless in the overall context of the investigation.

For example, in the aftermath of crimes that receive considerable media attention the subject can be exposed to the test stimuli in many ways. Such exposure could occur by way of reading about the crime in newspapers or magazines, watching television, listening to the radio or by word of mouth.

Conclusion
Scientific developments have made the modern investigations more eminent in terms of results and therefore established the irrevocable need for such. The revolution of scientific technology is waving like fast flowing air in the modern world of advancement. The field of law is also under the shadow of scientific advancement. Judicial system, particularly the criminal justice system, is not untouched with the advancement of science.186

Regarding this forensic science has a paramount role in the detection of crime. It can be defined as a science, by means of which material evidence is collected, analyzed, presented and used in a court of law especially in relation to crimes. It embraces all branches of science and applies them to the problems of law. Though its techniques are borrowed from various scientific

disciplines, like chemistry, medicine, surgery, biology, photography, physics and mathematics but over the years, it has developed its own branches like Anthropology, D.N.A., Fingerprinting, Fingerprint Odontology etc.

In the 20th century, Forensic science tests, such as lie detection tests, DNA Finger printing and Fingerprint comparison tests has revolutionized the modern investigation system. Lie detection tests include three types of tests. Firstly, narco-analysis test, which involves the intravenous administration of drug that causes the subject to enter into hypnotic trance and becomes less inhibited.

The drug induced hypnotic stage is useful for investigators since it makes the subject more likely to divulge information. The drug used for this test is sodium pentothal, high quantities for which are routinely used for inducing general anaesthesia in surgical procedure. This test is a scientific procedure to obtain information from an accused

in a natural sleep-like stage. 187 The second test is polygraph test. The polygraph works on the principle that change in the person's perception or consciously held feelings produces a defence reaction in the form of psychological changes 103i.e. in the pulse rate, blood pressure, respiration rate and electrical resistance at the skin, known as G.S.R.

During the polygraph test a corrugated rubber tube, tied around the subject's chest, measures respiratory changes, and inflated cuff wrapped round the upper arm, which measures the cardio vascular changes; electrodes attached to the palm or fingers, measures the electro dermal response; and the trans duct attached to the thumb measures blood volume reflecting the pulse rate.

A baseline is established by asking questions whose answers the investigators know. Lying by a suspect is accompanied by specific, perceptible, psychological and behaviour changes and the sensors and a wave pattern in the graph expose this. Deviation from the baseline is taken as sign at lie. P300 or Brain Mapping. Waves are generally reflected when the person has some connection with those pictures or sounds.

The entire system is controlled by a computer. If the stimulus gives a positive response, it is considered that the accused has some liaison with the incident. The fourth forensic science tests id DNA Fingerprinting. DNA stands for Deoxyribonucleic Acid. It is the biological blueprint of life. DNA Fingerprinting is applicable to virtually all body materials, are encountered in a variety of heinous crimes, murders, dacoities, encounter and other body offences against the person.

Award Winning Article Is Written By: Mr.Harshni Slathia

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