Forensic science is defined as the application of science in answering questions that are of legal interest. More specifically, forensic scientists employ techniques and tools to interpret crime scene evidence, and use that information in investigations. Forensic scientists and technicians come from a variety of academic backgrounds, although most have completed coursework in the life sciences, chemistry and law enforcement.
Types of Evidence:
Forensic scientists often work as generalists, meaning that they have expertise in working with a wide variety of evidence types. However, many also specialize in the use of certain techniques and tools. Different types of evidence require different skills and equipment. Types of evidence that are most frequently analyzed during investigations include: trace evidence and biological and ballistic evidence. Trace evidence is found wherever an object or person has had contact with another object or person and each of the objects leaves behind some sign of its having been there. Fingerprints and tire tracks are examples of trace evidence. Biological evidence will be found wherever there is bodily fluid or human or animal remains, and can include DNA testing. Ballistics is the study of firearms and, in particular, the path that a bullet takes during flight.
i) Biological Evidence:
In examining biological evidence, forensic scientists use tools both at the scene, and in the lab. When a forensic scientist arrives at a crime scene, he may look for human remains, blood or other bodily fluids and collect samples of any that are found. Because not all bodily fluids (particularly those that have been cleaned up after) are visible to the naked eye, the scientist can use the chemical Luminol to show latent traces of blood. Where large quantities of blood are present, an expert in blood spatter analysis can examine the patterns and size of the bloody areas to determine information such as the trajectory of the blood. This data can help an investigator deduce what type of weapon was used, or where the perpetrator and victim were standing during the attack.
ii) DNA Evidence:
DNA evidence uses the unique genetic markers that identify individuals to determine whether a person was at a scene, or to identify a piece of property as belonging to a specific person. In order to identify an individual's DNA it must be extracted from a piece of property that a person has had contact with, and has left a bodily fluid such as semen, blood or saliva on. The scientist performs tests that identify genetic markers and create a profile that is unique to that person, and can be compared to a sample taken from any individual. Scientists may also attempt to get enough blood from evidence to conduct toxicology testing, to determine the presence of alcohol, drugs, poisons or chemicals.
iii) Trace Evidence:
Trace evidence is found where two objects have made contact with each other. When a person or an object touches another object, some 'trace' of the two will be exchanged. This is the theory behind the analysis of fingerprints, tire and footprints, and fiber analysis. Technicians lift fingerprints from surfaces by dusting the area with a powder which sticks to the oils in the fingerprint. She then employs fingerprint lifting tape to take the print from the surface to the lab, where it can be analyzed. In the case of a footprint, tire track or other pattern that was left in an outdoor area, a forensic scientist can fill in the depression with plaster, which can be removed after it sets up. The casting is taken to a lab where it is stored until needed, or compared against a known sample, such as a suspect's shoe.
Some forensic scientists specialize in the field of ballistics testing. Ballistics is a science that involves the science of the flight path that a bullet takes as it travels to its target. Trained ballistics specialists can glean a tremendous amount of information about the type of weapon that was used, the path of the bullet and more through the examination of the bullet itself. Guns produce a specific pattern of wear and grooves on bullets as they are fired, and this pattern is unique. By examining the bullets and test-firing weapons, an investigator can frequently either identify the type of firearm that was used, where it was fired from, or even match the bullet with a specific weapon.
Scope of Forensic Science:
Forensic science has shaped the world of justice, fuelling crime investigations and signifying the progress of modern technology. Forensic science of today covers :
· Modern computer/clay facial reconstruction;
· DNA fingerprinting;
· Autopsy techniques;
· Forensic anthropology;
· Toxicology and much more.
What more reliable method is there to prove innocent or guilty other than through science?
Psychological evaluation is regarded as the key to human brain in crime investigation.
There are certain steps to be followed in psychological evaluation, which includes:
i) Psychological profiling
ii) Psychological assessment
iv) Brain Electrical Oscillation Signature Profile (BEOS)
Psychological Profiling is the study of the psychological background of the person. This is done for the complete understanding of the individual. It consists of the following:
a) Personal History: Family, childhood behaviour, education, occupation, health, sex marriage, emotional and fantasy life, habits, moral life alcohol or substance use, religious and other cultural ballets, interpersonal and social relationships.
b) Mental Status Examination: Presence of psychiatric and neurological symptoms, abnormality in orientation, attention, concentration, memory, speech, perception, mood, thought processes, judgement, incite and other behavioural manipulations are assessed.
This assessment helps us to understand the personality, attitudes, beliefs, moral values, behavioural patterns of the individuals and specially their tendency to commit crimes.
Assessment also aims at cheching for the presence or absence of various forms of abnormal behaviour and personality disorders that can lead to criminal behaviour.
It also reveals a person’s tendencies to lie, fake, manipulate, put himself in good or bad light etc. especially in a standard social situation.
It measures physiological responses produced by inducing stress by asking questions.
This is done by:
· Verifying the veracity of statements of suspect, witness and complainant in crimes.
· Economize the process of investigation by creening large number of suspects.
· Corroborates or rules out the possibility of someone’s involvement and helps investigation.
· Variety of testing formats available based on the nature of case and information available.
Brain Electrical Oscillation Signature Profile (BEOS):
This was developed by Dr. Mukundan based on the concept of Experiential Knowledge (EK). EK is the memory acquired when an individual participates and is fully involved in an event (Crime) which becomes an experience.
Probes related to the crime activates memory (EK) related to the experience of committing the crime causing significant electrical changes in the brain.
Scope of BEOS:
· Checks for the individuals involvement in a crime.
· Differentiates the extent of participation of each individual in the crime.
· Various possibilities about the way the crime was committed can be tested.
· Acquires information directly from the brain and does not require the person’s participation leaving no scope for manipulation.
It is an invasive technique in which sodium pentothal, a drug is injected to the subject to induce a semiconscious state and disinhibition and he is interviewed on the details of the crime.
Sodium Pentothal removes conscious control and makes the person disinhibited. It makes him more relaxed, comfortable, open, free and conversant.
Narcoanalysis is conducted at an operation theatre with the necessary facilities for life support wherein the psychologist injects the drug and retrieves vital physiological parameters and forensic psychologist conducts the interview.
Scope of Narcoanalysis:
· Scientific technique but can help elicit concealed information related to the crime.
· Helpful especially in cases of larger social interest like terrorism
· Results admissible in the court can help further investigation in a case.
· Court order is mandatory for Narco analysis.
It is the art and science of applying computer science to aid the legal process. Although plenty of science is attributable to computer forensics, most successful investigators possess a nose for investigations and a skill for solving puzzles, which is where the art comes in. - Chris L.T. Brown, Computer Evidence Collection and Preservation, 2006.
Thus, it is more than the technological, systematic inspection of the computer system and its contents for evidence or supportive evidence of a civil wrong or a criminal act. Computer forensics requires specialized expertise and tools that goes above and beyond the normal data collection and preservation techniques available to end-users or system support personnel. One definition is analogous to "Electronic Evidentiary Recovery, known also as e-discovery, requires the proper tools and knowledge to meet the Court's criteria, whereas Computer Forensics is simply the application of computer investigation and analysis techniques in the interests of determining potential legal evidence." Another is "a process to answer questions about digital states and events". This process often involves the investigation and examination computer system(s), including, but not limitied to the data acquisition that resides on the media within the computer. The forensic examiner renders an opinion, based upon the examination of the material that has been recovered. After rendering an opinion and report, to determine whether they are or have been used for criminal, civil or unauthorized activities. Mostly, computer forensics experts investigate data storage devices, these include but are not limited to hard drives, portable data devices (USB Drives, External drives, Micro Drives and many more).
Scope of Cyber Forensics:
Cyber experts provides various Forensic Science services including- Forensic Expert Opinions Under Section 45 of Indian Evidence Act on Questioned Document & Handwriting Analysis, Fingerprints, Forged Electronic Documents, Digital Document Frauds, Disguised Documents, Spoofed Emails, Phishing emails, Phishing sites, Copyrighted Websites, Original Author, Real Creator, Designer or Owner of Computer Files, eContracts, eAgreements, Authenticity of Images, Photo, Camera, Video, Audio Files, Film, Tape, Picture, Deleted Data Recovery, Digital Evidence Recovery, Location of Email, IP Location, Website Registrar, Fake Content, Fake Profiles, Porn Clips, Vulgar Emails, Spam Mails, Lottery Emails, Secure Deletion of Sensitive Information, Retrieving user history, password recovery, login details recovery, MMS, Sim Card Data Recovery, Call History on Mobile Phone, Deleted SMS Recovery, Electronic Evidences Collection, Mirror Imaging, Hash Value, Scanned Documents, Duplicate Documents, Decipher, Invisible Writing, Hidden Evidences, Blackmailing Messages, Suicide Notes, Disputed Documents, Legal Softwares, Forensic Work Stations, EnCase, Forensic Tool Kit, iLook, Xway, Cyber watch, Guidance, Access Databases, Outlook Express Email Recovery, Web Mail Traces, PDF Files, Excel Files, Litigation, Threatening or Anonymous Emails / Chat, File or Folder Age / Date / Time Analysis, Cross Examination, Expert Testimony, Typewritten Document Examination, Computer Printout Examination, Infrared / Ultra Violet Examination of Printed Papers, fake agreements, Consumer Court related documents, Expert Consultation, Breach of Confidentiality, Legal Consultancy, Wrongful Termination, Forensic Imaging, Forensic Photography, and many more...
Common types of Cyber Crime in India:
· Financial Crimes
· Cyber Pornography
· Sale od illegal article
· Online gambling
· Intellectual Property Crimes
· Email Spoofing
· Cyber Defamation
· Cyber stalking
Digital Evidence Recovery:
· Searching slack space
· Searching unallocated clusters
· Reconstructing the partitions if needed
· Extracting deleted files
· Reading operating system registry and logs
· Extracting emails, web addresses, internet history, credit card numbers etc.
· Recovering the passwords set to the files
· Reading contents in printer spool files
· Reading mobile phone memory
· Reading contents of sim cards
· Reading contents of additional memory cards
· Extracting existing and deleted call logs, messages, address book, images etc.
Steps involved in Cyber forensics:
· Identification: identify the media to be seized
· Seizure: use the right technique to seize the media
· Acquisition: making a forensic duplicate of the media
· Authentication: validation of forensic duplicate
· Analysis: techniques to look for evidence
· Presentation: putting together all the findings
· Preservation: storage of the suspect media
It is the way of identifying a person solely by their speech. The aim of speaker identification is to compare the sample from the unknown speaker with the known set of samples and determine whether it was produced by any of the known speakers.
Importance of Speaker Identification Technique in Crime Investigation:
It plays a major role in solving the following types of cases:
· Bribery cases
· Kidnapping for ransom
· Call girl rackets
· Obscene telephone calls
· Bomb threat calls
· Terrorist to claim credit for a terrorist action
· False telephonic message
· False fire alarms
To determine whether or not a tape has been edited, tampered with, or altered in any way. Video authentication is a process that is used to ascertain the trustworthiness of a digital video.
In other words, a video authentication system ensures the integrity of digital video, and verifies that the video taken into use has not been tampered.
It is a science embodying the knowledge, source, character, fatal effect, lethal dose, analysis of poisons and the remedial measures.
It is a substance which is capable of producing injury or death to living beings, when ingested or absorbed.
Eg: LD 50 (Lethal Dose): It is a dose of a substance causing death of 50% animals.
Extremely toxic substance weighs less than 5mg
Toxicology can pull the following sections:
· Section 174 of Cr.P.C: Poison Consumption
· Section 302 of IPC: Murder
· Section 279 of IPC and Motor Vehicle Act: Accidents
· Section 309 of IPC: Suicide
· Section 498(A) of IPC: Dowry Death
TLC: (Thin Layer Chromatography):
This is a simple and sensitive technique routinely used in forensic science laboratories. In this technique glass plates of size 20x20 cm are coated with slurry of silica gel G. dried in oven at 110 oC. Extracts of the matrices are spotted on these plates. Then plates are eluted in the developing chamber containing solvent mixtures hexane: Acetone 8:8 v/v as a mobile phase. When solvent reaches upto 10cm height, plates are removed, dried and sprayed with different visualizing reagents. In TLC Rf – value is an important measure.
All pesticides, insecticdes, plant growth regulators, weedicides, herbicides, fungicides and most of the drugs can be detected using this technique.
Visualization reagents for insecticides:
Organophosphorous: Rogor, Thimet: Mercurous nitrate, Mercuric nitrate-DPC
Organochlorine: Endosulfan: NaOH followed by Nickel Amine
Carbamate insecticides: Bagon: Tollen’s reagent, Diazophenol reagent
Pyrethroids: NaOH followed by FeSO4 followed by HCl, Resorcinon in NaOH
For Phenois, Cresois: Iodine vapours, FeCl3 followed by K4Fe(CN)6
Drugs, Plant Poisons: Dragandorff’s reagent, acidic KMnO4, Chromic acid
Steps to be followed in investigation of death by Poison Consumption:
· Crime Scene Observation
· Hospitalisation to victim
· Collection of stomach aspirates by M.O.
· Collection of poison bottles, drug strip
· Suspicious articles
· Stained clothes
Collection of Viscera in post mortem be CMO:
· Stomach intestine contents,
· Heart, Liver, spleen, lungs, kidneys
Tools that are used in Forensic Examination & Investigation:
Forensic examination and investigation is a field of science that is employed every day to help bring criminals to justice. Television shows, such as "CSI: Crime Scene Investigation," have popularized the field. But in real life, forensic examination involves long hours of careful observation, testing and study. A number of special tools and techniques have been developed to help investigators do their job.
While not as accurate as genetic fingerprinting, testing for a blood type is still a useful tool for helping to determine guilt or innocence. If a victim has type A blood and a drop on a suspect's shirt turns out to be type B, it cannot have come from the victim.
These specialized microscopes allow forensic scientists to compare two bullets at the same time. An evidence bullet is compared to one fired from a suspect's gun under controlled circumstances. The comparison lets scientists tell if the evidence bullet was also fired from the suspect's gun.
Neutron Activation Analysis
This process allows forensic scientists to compare shards of a shattered bullet on an atomic level. The shards can then be compared with the metallic makeup of bullets found in a suspect's possession.
Autopsies are used to determine the time and cause of death. For example, if a person has drowned, the blood on the left side of the heart will be diluted with water. If a body has been found in a pool with undiluted blood, forensic scientists know that the person was not breathing when they went into the water and was possibly killed first.
Electron microscopes can magnify surfaces as much as 200,000 times.
Mass spectrometers and gas cinematographers are used to analyze and separate chemical components, which is particularly useful in drug-related crimes.
Forensic science plays an integral role in the criminal justice system. Well-trained forensic scientists and medical examiners can be the determining factor in the ability of evidence to adequately represent the facts of a case. Forensic science can be used in almost any criminal case; however, investigations of homicide, rape, and arson are those that benefit the most from forensic science.
Everyone is familiar with the television show “C.S.I.” While this show involves a lot of idealism, and often times skews the reality of forensic science, at its core “C.S.I.” represents the importance that quality forensic science can play in a complicated case. In complicated cases, and even in relatively simple ones, the most minute of details can become paramount to a successful prosecution or defense. Forensic scientists are trained to analyze crime scenes, evidence, and personal testimony to create a visualization of how a crime occurred. An understanding of the circumstances surrounding a crime is pivotal to ensuring that the correct charges are brought against the correct person. The mishandling or misinterpretation of evidence can be devastating to the goals of the criminal justice system and can result in the wrongful conviction of innocent persons and the failure to convict the true perpetrator, which is why you need a skilled criminal defense lawyer in Knoxville if you’ve been convicted of a criminal offense. Conversely, correctly applied forensic science ensures that justice is served and innocent persons remain free.
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