INTRODUCTION
Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to a legal system. This may be in relation to a crime or a civil action. Besides its relevance to a legal system, more generally forensics encompasses the accepted scholarly or scientific methodology and norms under which the facts regarding an event, or an artifact, or some other physical item (such as a corpse) are ascertained as being the case. In that regard the concept is related to the notion of authentication, where by an interest outside of a legal form exists in determining whether an object is what it purports to be, or is alleged as being. The word forensic comes from the Latin adjective forensis, meaning "of or before the forum". In Roman times, a criminal charge meant presenting the case before a group of public individuals in the forum. Both the person accused of the crime and the accuser would give speeches based on their side of the story. The individual with the best argument and delivery would determine the outcome of the case. This origin is the source of the two modern usages of the word forensic as a form of legal evidence and as a category of public presentation.
In modern use, the term "forensics" in place of "forensic science" can be considered incorrect as the term "forensic" is effectively a synonym for "legal" or "related to courts". However, the term is now so closely associated with the scientific field that many dictionaries include the meaning that equates the word "forensics" with "forensic science".
Modern History
In sixteenth century Europe, medical practitioners in army and university settings began to gather information on cause and manner of death. Ambroise Pare a French army surgeon, systematically studied the effects of violent death on internal organs. Two Italian surgeons, Fortunato Fidelis and Paolo Zacchia, laid the foundation of modern pathology by studying changes which occurred in the structure of the body as the result of disease. In the late 1700s, writings on these topics began to appear. These included: A Treatise on Forensic Medicine and Public Health by the French physician Fodere, and The Complete System of Police Medicine by the German medical expert Johann Peter Franck.
In 1776, Swedish chemist Carl Wilhelm Scheele devised a way of detecting arsenous oxide, simple arsenic, in corpses, although only in large quantities. This investigation was expanded, in 1806, by German chemist Valentin Ross, who learned to detect the poison in the walls of a victim's stomach, and by English chemist James Marsh, who used chemical processes to confirm arsenic as the cause of death in an 1836 murder trial.
Two early examples of English forensic science in individual legal proceedings demonstrate the increasing use of logic and procedure in criminal investigations. In 1784, in Lancaster, England, John Toms was tried and convicted for murdering Edward Culshaw with a pistol. When the dead body of Culshaw was examined, a pistol was (crushed paper used to secure powder and balls in the muzzle) found in his head wound matched perfectly with a torn newspaper found in Toms' pocket. In Warwick, England, in 1816, a farm labourer was tried and convicted of the murder of a young maidservant. She had been drowned in a shallow pool and bore the marks of violent assault. The police found footprints and an impression from corduroy cloth with a sewn patch in the damp earth near the pool. There were also scattered grains of wheat and chaff. The breeches of a farm labourer who had been threshing wheat nearby were examined and corresponded exactly to the impression in the earth near the pool. Later in the 20th century, several British pathologists, Bernard Spilsbury, Francis Camps, Sydney Smith and Keith Simpson would pioneer new forensic science methods in Britain.
FORENSIC IDENTIFICATION
Any type of organism can be identified by examination of DNA sequences unique to that species. Identifying individuals within a species is less precise at this time, although when DNA sequencing technologies progress farther, direct comparison of very large DNA segments, and possibly even whole genomes, will become feasible and practical and will allow precise individual identification. To identify individuals, forensic scientists scan 13 DNA regions, or loci, that vary from person to person and use the data to create a DNA profile of that individual (sometimes called a DNA fingerprint). There is an extremely small chance that another person has the same DNA profile for a particular set of 13 regions.
DNA TECHNOLOGIES USED IN FORENSIC INVESTIGATION
Restriction Fragment Length Polymorphism (RFLP)
RFLP is a technique for analyzing the variable lengths of DNA fragments that result from digesting a DNA sample with a special kind of enzyme. This enzyme, a restriction endonuclease, cuts DNA at a specific sequence pattern know as a restriction endonuclease recognition site. The presence or absence of certain recognition sites in a DNA sample generates variable lengths of DNA fragments, which are separated using gel electrophoresis. They are then hybridized with DNA probes that bind to a complementary DNA sequence in the sample. RFLP was one of the first applications of DNA analysis to forensic investigation. With the development of newer, more efficient DNA-analysis techniques, RFLP is not used as much as it once was because it requires relatively large amounts of DNA. In addition, samples degraded by environmental factors, such as dirt or mold, do not work well with RFLP.
PCR Analysis
Polymerase chain reaction (PCR) is used to make millions of exact copies of DNA from a biological sample. DNA amplification with PCR allows DNA analysis on biological samples as small as a few skin cells. With RFLP, DNA samples would have to be about the size of a quarter. The ability of PCR to amplify such tiny quantities of DNA enables even highly degraded samples to be analyzed. Great care, however, must be taken to prevent contamination with other biological materials during the identifying, collecting, and preserving of a sample.
STR Analysis
Short tandem repeat (STR) technology is used to evaluate specific regions (loci) within nuclear DNA. Variability in STR regions can be used to distinguish one DNA profile from another. The Federal Bureau of Investigation (FBI) uses a standard set of 13 specific STR regions for CODIS. CODIS is a software program that operates local, state, and national databases of DNA profiles from convicted offenders, unsolved crime scene evidence, and missing persons. The odd that two individuals will have the same 13-loci DNA profile is about one in a billion.
Mitochondrial DNA Analysis
Mitochondrial DNA analysis (mtDNA) can be used to examine the DNA from samples that cannot be analyzed by RFLP or STR. Nuclear DNA must be extracted from samples for use in RFLP, PCR, and STR; however, mtDNA analysis uses DNA extracted from another cellular organelle called a mitochondrion. While older biological samples that lack nucleated cellular material, such as hair, bones, and teeth, cannot be analyzed with STR and RFLP, they can be analyzed with mtDNA. In the investigation of cases that have gone unsolved for many years, mtDNA is extremely valuable.
All mothers have the same mitochondrial DNA as their offspring. This is because the mitochondrion of each new embryo comes from the mother's egg cell. The father's sperm contributes only nuclear DNA. Comparing the mtDNA profile of unidentified remains with the profile of a potential maternal relative can be an important technique in missing-person investigations.
Y-Chromosome Analysis
The Y chromosome is passed directly from father to son, so analysis of genetic markers on the Y chromosome is especially useful for tracing relationships among males or for analyzing biological evidence involving multiple male contributors.
In the human, there are normally 46 chromosomes, two sex chromosomes and 22 chromosome pairs for which one copy is inherited from each parent at conception. The sex chromosomes are called the X and the Y chromosome. Everyone needs at least one X chromosome to survive. Females normally have two X chromosomes whereas males typically have one X and one Y chromosome. In the absence of a Y chromosome, babies will develop as females. When the Y chromosome is present, they will develop as males. The Y chromosome is different from all of the other chromosomes in a couple of different ways. First, it contains the fewest number of genes of any chromosome, far fewer than chromosome 21, the next smallest chromosome. Second, the vast majority of the Y chromosome is composed of heterochromatin, a form of DNA that does not contain functional genes. Third, the genes that are present on the Y chromosome are critically important in sexual development. As only males have a Y chromosome, and the presence of the Y chromosome determines male sexual development, the pattern of inheritance is that fathers uniformly transmit the Y chromosome to their sons at conception, and never to their daughters. This allows a tracing of inheritance patterns for genes and other markers on the Y chromosome from father to son down through many generations.
Because the Y chromosome has so much noncoding DNA, there are many different DNA sequence variants that may be identified on the Y chromosome. These non-coding DNA sequences have a very high rate of mutation, and many potentially informative short tandem repeat (STR) sequences that permit a detailed study of paternity and other forensic testing based on DNA sequences. The Y chromosome has a distinctive pattern of fluorescence (light emission) naturally and also when using certain organic dyes. These properties can be exploited in various ways to identify the presence of semen based on natural fluorescence, or to identify Y-bearing sperm and separate them from X-bearing sperm. Furthermore, chromosomal analysis for the sex chromosomes can be used to predict the sex of a baby prenatally. As of 2005, it is not considered ethical to use chromosome analysis prenatally to facilitate sex selection for parents who desire either a boy or a girl unless there is a sex-linked genetic disease risk.
SOME INTERESTING USES OF DNA FORENSIC IDENTIFICATION
v Identifying September 11th Victims
Identifying the victims of the September 11, 2001, World Trade Center attack presented a unique forensic challenge because the number and identity of the victims were unknown and many victims were represented only by bone and tissue fragments. At the time of the attack, no systems were in place for rapidly identifying victims in disasters with more than 500 fatalities. The National Institutes of Justice assembled a panel of experts from the National Institutes of Health and other institutions to develop processes to identify victims using DNA collected at the site. Panel members produced forms and kits needed to enable the medical examiner’s office to collect reference DNA from victims’ previously stored medical specimens. These specimens were collected and entered into a database. The medical examiner's office also received about 20,000 pieces of human remains from the World Trade Center site, and a database of the victims’ DNA profiles was created. New information technology infrastructure was developed for data transfer between the state police and medical examiner’s office and to interconnect the databases and analytical tools used by panel members. In 2005 the search was declared at an end because many of the unidentified remains were too small or too damaged to be identified by the DNA extraction methods available at that time. Remains of only 1585, of the 2792 people known to have died had been identified. In 2007, the medical examiner's office reopened the search after the Bode Technology Group developed a new methodology of DNA extraction that required much less sample material than previously necessary. The victim DNA database and the new methods have allowed more victims to be identified, and further identifications will be possible as forensic DNA technology improves.
v A case in Italy involving the murder of a woman used this technique to identify a suspect.
The woman’s body was discovered partially covered by sand on a beach in Sicily. Investigators suspected a prominent businessman, whose car was seen in the area the night of the murder. A search of the suspect’s home produced no substantial evidence, apart from a mosquito blood meal stain on the wall. Technicians absorbed the stain onto wet filter paper and then scratched the rest of the blood material off the wall. They also collected the insect’s remains in a tube for species identification. They extracted DNA from the blood sample and performed PCR. They identified the DNA as the victim’s, which placed the victim in the vicinity, if not in, the suspect’s home. Experts identified the mosquito as C. pipiens, a species not known to travel far distances, such as between the suspect’s home and the crime scene. This evidence, along with grains of sand and leaf fragments on the suspect’s clothing that matched samples from the beach, helped convict the suspect of second degree murder. This also relates forensic entomology and the law.
v 6 Year Old Rape Case Solved by DNA (2009)
The Snohomish County Sheriff’s Office arrested a 40-year-old man from Lynwood for the sexual assault in Washington of a 13-year-old girl. The rape case was 6 years old, and DNA evidence recently surfaced that linked the man to the crime. The man was arrested near his apartment without incident. The Lynwood man had been arrested for drunk driving in 2008, and agreed to give a DNA sample at that time. The sample was put into the FBI database, and was declared a match to DNA samples found at the scene of the rape, which occurred at the victim’s house. Though the man had previously been convicted of burglary, he had never been charged with a sex crime. According to the police report, the man broke into the home and sexually assaulted the girl while two of her friends slept soundly nearby. The man threatened the victim, raped her, and then fled the scene of the incident. Though DNA evidence has been gathered at the scene, police were unable to link the evidence to any individual who was currently in their database, and the case eventually grew stagnant until the emergence of matching evidence from the drunken driving arrest.
v OJ Simpson Murder Case
On the night of the 12th of June 1994, Orenthal James Simpson's ex-wife, Nicole and her friend, Ronald Goldman, were discovered murdered at Nicole's Beverly Hills abode by her next door neighbor. The police were notified and arrived immediately at the horrific scene to find Nicole's severed body almost decapitated and her friend's body, evidently fallen victim to a hysterical stabbing attack. Upon further investigation of the scene, a bloodstained left-hand glove was discovered and her two sons were still inside the house, asleep in spite of the night's events.
Homicide experts were called in and other officers made their way to Simpson's house, a five minute drive away, where they then discovered that he had taken a night flight to Chicago. The police noticed blood all over Simpson's car, which was parked outside the house. They also saw a trail of blood drops leading from Simpson's car to the front door of the house, where they discovered another bloodstained glove identical to the one found near Nicole's body. Simpson was contacted by police at his hotel in Chicago and although he sounded distraught about his ex-wife's death, he didn't sound curious to find out what happened. He caught the next plane home and the police interviewed him on the same day. He had a bandaged hand which he claimed was cut some time ago and the wound had reopened when he accidentally cut it on some glass. His hand was photographed, blood samples taken and fingerprints recorded, then after all of this, he was free to go. The search of his house was videotaped and by the afternoon of the same day, all of the evidence needed was removed, recorded and taken to a laboratory along with evidence taken from Simpson himself.
Simpson was put on trial, one of the most highly publicized trials in history, and all of the evidence seemed to point to him being responsible for the murder. He had no alibi, DNA analysis showed his blood was present on a sock found in Nicole's room, both gloves were stained with blood from both his victims and the trail of blood leading from the car to his house seemed to heighten all suspicions. The case, however, was turned around with Simpson's expert lawyers claiming that a certain police officer present at the initial scene, was racist against black people and that the officer had plenty of time to 'set' the scene up while Simpson was in Chicago. The recorded tape of the investigation of Simpson's house also revealed a large number of mistakes such as unsterile swabbing methods and unnoticed vital clues. Because of these claims from Simpsons lawyers, the jury was convinced that Simpson was innocent and after a nine-month trial, Simpson was cleared of murder charges and that was that.
RECENT TECHNIQUES USED IN MEDICAL FORENSIC SCIENCE
I. Forensic Entomology
Forensic entomology is the application and study of insect and other arthropod biology to criminal matters. Forensic entomology is primarily associated with death investigations; however, it may also be used to detect drugs and poisons, determine the location of an incident, detect the length of a period of neglect in the elderly or children, and find the presence and time of the infliction of wounds. Forensic entomology can be divided into three subfields: urban, stored-product and medico-legal/medico-criminal entomology.
Urban forensic entomology: Urban forensic entomology typically concerns pest infestations in buildings or gardens that may be the basis of litigation between private parties and service providers such as landlords or exterminators. Urban forensic entomology studies may also indicate the appropriateness of certain pesticide treatments and may also be used in stored products cases where it can help to determine chain of custody, when all points of possible infestation are examined in order to determine who is at fault.
Stored-product forensic entomology: Stored-product forensic entomology is often used in litigation over infestation or contamination of commercially distributed foods by insects. Stored product entomology is most commonly used in lawsuits over the contamination or infestation of foods by insects, usually in the commercial sector. Although stored product entomology may seem a lesser-known subject, this branch of forensic entomology is extremely important, as it encompasses all cases involving the finding of insects in any food products. A stored product entomologist's job is determining if the product was truly infested before it was shipped, or purchased by the consumer, and whether or not legal action should be taken against the producer. These entomologists are so important, and these cases so common, that many large food companies actually hire a forensic entomologist to keep on staff to assist in court proceedings involving a contaminated product. Companies are required by the U.S. Food and Drug Administration (FDA) to have no more than a certain number of larva/insects/insect fragments in their product, and it is when this defect action level is exceeded that a consumer can prosecute.
Medico-legal forensic entomology: Medicolegal forensic entomology covers evidence that may be gathered through arthropod studies at events such as murder, suicide, rape, physical abuse and contraband trafficking. In murder investigations it deals with which insects lay eggs when and where, and in what order they appear in dead bodies. This can be helpful in determining a post mortem interval (PMI) and location of a death in question. Since many insects exhibit a degree of endemism (occurring only in certain places), or have a well-defined phenology (active only at a certain season, or time of day), their presence in association with other evidence can demonstrate potential links to times and locations where other events may have occurred. Another area covered by medicolegal forensic entomology is the relatively new field of entomotoxicology. This particular branch involves the utilization of entomological specimens found at a scene in order to test for different drugs that may have possibly played a role in the death of the victim.
There are many different types of insect studied in forensic entomology. The insects listed below are mostly necrophagous (corpse-eating) and are particularly relevant to medicolegal entomological investigations. Some of the insects are:
Flies, beetles, mites, moths, wasps, ants and bees.
Application of Forensic Entomology
Crime Scene Insects Reveal the Time of Death of a Corpse: When a suspicious death occurs, a forensic entomologist may be called to assist in processing the crime scene. Insects found on or near the body may reveal important clues about the crime, including the victim's time of death. Insects colonize cadavers in a predictable sequence, also known as insect succession. The first to arrive are the necrophagous species, drawn by the strong scent of decomposition. Blow flies can invade a corpse within minutes of death, and flesh flies follow close behind. Soon after come the dermestid beetles, the same beetles used by taxidermists to clean skulls of their flesh. More flies gather, including house flies. Predatory and parasitic insects arrive to feed on the maggots and beetle larvae. Eventually, as the corpse dries, hide beetles and clothes moths find the remains.
Forensic entomologists collect samples of crime scene insects, making sure to take representatives of every species at their latest stage of development. Because arthropod development is linked directly to temperature, she also gathers daily temperature data from the nearest available weather station. In the lab, the scientist identifies each insect to species, and determines their exact developmental stage. Since identification of maggots can be difficult, the entomologist usually raises some of the maggots to adulthood to confirm their species. Blow flies and flesh flies are the most useful crime scene insects for determining the postmortem interval, or time of death. Through laboratory studies, scientists have established the developmental rates of necrophagous species, based on constant temperatures in a laboratory environment. These databases relate a species' life stage to its age when developing at a constant temperature, and provide the entomologist with a measurement called accumulated degree days, or ADD (Accumulated Degree Days). ADD represents physiological time.
Using the known ADD, she can then calculate the likely age of a specimen from the corpse, adjusting for the temperatures and other environmental conditions at the crime scene. Working backwards through physiological time, the forensic entomologist can provide investigators with a specific time period when the body was first colonized by necrophagous insects. Since these insects almost always find the corpse within minutes or hours of the person's death, this calculation reveals the postmortem interval with good accuracy.
Crime Scene Insects Prove That Drugs or Toxins Played a Role in a Death:
When a suspicious death is investigated, the medical examiner usually takes soft tissue samples to test for the presence of drugs or toxins. Because soft tissues decompose quickly, it may be impossible to obtain samples for standard toxicology tests. Insects present on the corpse, however, may provide evidence to whether drugs or toxins played a role in the death. Because certain insects feed on the soft tissues of the human cadaver, these insects also consume whatever substances reside within those tissues, including drugs or poisons. When human tissues are no longer present, tests on the insects themselves may reveal any illicit or therapeutic drugs or other unnatural substances that were present at the time of death. In some instances, even insect feces or castings can prove the presence of toxins or drugs.
Entomotoxicology, as this branch of forensic entomology is known, effectively began with a case study by J.C. Meyer, published in 1980. In this case, the body of a 22-year-old woman was found, along with an empty prescription bottle for Phenobarbital. The woman had a history of suicide attempts, and had left a note suggesting she planned to take her own life. Authorities suspected she died of an intentional overdose on Phenobarbital. However, her body had been exposed to the elements for two weeks, leaving no usable tissue to test for a drug overdose. Secondary screw-worm maggots collected from the corpse were tested instead, and proved to be full of Phenobarbital. Cause of death? Overdose. Case closed. Forensic studies on insects can also provide information about toxins in a cadaver, which can help determine where the victim has been. In another interesting case, this one from Finland, insects helped police determine the identity of a victim. Again, the body was too decomposed to provide useful tissue samples, but insects were collected from the corpse. Tests on the insects showed the victim's tissues contained several contaminants, including mercury. The contaminants were not present in these levels at the site where the body was found. Investigators learned, though, of another region of the country where similar contaminants were known to exist. A sketch of the victim was shown to people in the mercury-contaminated community, and the victim was positively identified.
II. Forensic Odontology
Forensic dentistry or Forensic odontology is the proper handling, examination and evaluation of dental evidence, which will be then presented in the interest of justice. The evidence that may be derived from teeth, is the age (in children) and identification of the person to whom the teeth belong. This is done using dental records or ante-mortem (prior to death) photographs. Forensic odontology is derived from Latin, meaning forum or where legal matters are discussed. The first forensic dentist in the United States was Paul Revere who was known for the identification of fallen revolutionary soldiers.
The other type of evidence is that of bite marks, left on either the victim (by the attacker), the perpetrator (from the victim of an attack), or on an object found at the crime scene. Bite marks are often found on children who are abused.
Forensic dentists are responsible for six main areas of practice:
Identification of found human remains
Identification in mass fatalities
Assessment of bite mark injuries
Assessment of cases of abuse (child, spousal, elder)
Civil cases involving malpractice
Age estimation.
Forensic odontology is the study of dental applications in legal proceedings. The subject covers a wide variety of topics including individual identification, mass identification, and bite mark analysis. The study of odontology in a legal case can be a piece of incriminating evidence or an aspect of wide controversy. There have been many cases throughout history which have made use of bite marks as evidence. Bite marks are usually seen in cases involving sexual assault, murder, and child abuse and can be a major factor in leading to a conviction. Biting is often a sign of the perpetrator seeking to degrade the victim while also achieving complete domination. Bite marks can be found anywhere on a body, particularly on soft, fleshy tissue such as the stomach or buttocks. In addition, bite marks can be found on objects present at the scene of a crime. Bite marks are commonly found on a suspect when a victim attempts to defend him/herself. Even though using bite mark evidence began around 1870, the first published account involving a conviction based on bite marks as evidence was in the case of Doyle v. State, which occurred in Texas in 1954. The bite mark in this case was on a piece of cheese found at the crime scene of a burglary. The defendant was later asked to bite another piece of cheese for comparison. A firearms examiner and a dentist evaluated the bite marks independently and both concluded that the marks were made by the same set of teeth. The conviction in this case set the stage for bite marks found on objects and skin to be used as evidence in future cases. Another landmark case was People v. Marx, which occurred in California in 1975. A woman was murdered by strangulation after being sexually assaulted. She was bitten several times on her nose. Walter Marx was identified as a suspect and dental impressions were made of his teeth. Impressions and photographs were also taken of the woman’s injured nose. These samples along with other models and casts were evaluated using a variety of techniques, including two-dimensional and three-dimensional comparisons, and acetate overlays. Three experts testified that the bite marks on the woman’s nose were indeed made by Marx and he was convicted of voluntary manslaughter.
Applications of Forensic Odontology
Bite Mark Analysis: Upon collection of dental evidence, the forensic odontologist analyzes and compares the bite marks. Studies have been performed in an attempt to find the simplest, most efficient, and most reliable way of analyzing bite marks. Factors that may affect the accuracy of bite mark identification include time-dependent changes of the bite mark on living bodies, effects of where the bite mark was found, damage on soft tissue, and similarities in dentition among individuals. Other factors include poor photography, impressions, or measurement of dentition characteristics. On a crime scene the deontologists collects the evidences of bite mark if there any found on the assaulted body. The sample of bite mark is mostly found in cases of sexual assaults. Sometimes tooth sample is confused with any tooth sample of animals.
Estimation of age and sex: Forensic odontology involves dentist’s participation in assisting legal and criminal issues. It refers to the proper handling, examination and evaluation of dental evidence which will be then presented in furtherance of justice. The evidence that may be derived from the teeth is the age and the identification of the person to whom the teeth belongs. This is done by using dental records or ante mortem photographs. Besides, a forensic odontology report sets out the findings of a comparison between antemortem and postmortem evidence that indicates the odontologist’s opinion on the identification. The opinion needs to be defendable in a court of law. In forensics odontology different methods and techniques are used to determine age, sex identification of the victims or assailants. Sex determination can be done by using a major protein which has been found in human enamel called AMEL. Slight different in size and pattern of the nucleotide sequence in AMEL has been seen in male and female. A comprehensive dental record with number, position, morphology of teeth, a record of treatments which has been done on each tooth, all together have golden value in legal problems. Teeth are highly resistant to destruction and decomposition, so dental identification can be made under extreme circumstances. Morphology of a buried tooth remains the same even after months, but amalgam fillings become soft and liquid. A burnt tooth shrinks and its root curves. Severe burn makes crown to get powder. Different degree of temperature produces different changes to the tooth. At 150 degree centigrade it starts cracking and at 800 degree dentin is carbonized and becomes blue in color. If a burnt tooth is not recognizable by appearance, microscopic examination needs to be done. In age determination since the human body has different number of teeth in different period of life, therefore it helps to determine the age almost easily. If a single tooth is available (without body), Gustafson’s method is used to determine age. New techniques of body identification are based on DNA analysis. Polymerase chain reaction (PCR) which enable amplification of very tiny amount of DNA to concentration suitable for diagnostic analysis. Another method for identification purpose used is mt.DNA. The victim’s identification involves a comparison between DNA obtained from tooth fragment of victim and blood sample of biological relative’s. Bite marks also can be used in crime identification. For this purpose the bite marks is fixed in 10% formalin then saliva swab, photography and impression of the bite mark have been obtained. Acetate tracing from models of suspect is generated and comparisons between these two models have been done by considering the anatomic location, type of injury and shape of the bite marks. The analysis of the information will prove links to the suspect.
There are several legal cases solved by forensic odontology. One of the most famous case is, the determination of the decomposed body of minister of petroleum in Iran-Iraq war in the year 1980, in this case the body of the minister was found at decomposed stage after the war between the said two countries and by application of forensic odontology technique the body was identified after matching it with the antemortem evidences, the evidences included the photographs of the minister by which the sample of the jaw from the photograph and the jaw of the decomposed body was matched and the dead body was identified. In this case teeth was matched and then identified.
Florida v. Theodore Robert Bundy (June 25, 1979): In this case Bundy was charged of murder after rape, while rape Bundy left tide marks on the body of the women. The teeth evidences from the body of the women were found and were compared to the teeth sample of Bundy. The odontologist Dr. Souviron described the bite mark injuries found on Lisa Levy's body. As he spoke, the jury was shown full-scale photographs of the bite marks that had been taken the night of the murder. The doctor pointed out the uniqueness of the indentations left behind on the victim and compared them with full-scale pictures of Ted's teeth. There was no question that Ted had made the bite marks on Lisa Levy's body.
III. Forensic Pathology
Forensic pathology is a branch of pathology concerned with determining the cause of death by examination of a cadaver. Forensic pathology was first recognized in the USA by the American Board of Pathology in 1959. The autopsy is performed by the pathologist at the request of a coroner or medical examiner usually during the investigation of criminal law cases and civil law cases in some jurisdictions. Forensic pathologists are also frequently asked to confirm the identity of a cadaver. Forensic pathology is that branch of medicine which deals with the study of cause of death by examination of a dead body at the request of a coroner during legal cases. In forensic pathology the pathologist assist the criminal case by collecting and examining tissues specimens under the microscope in order to identify the presence or absence of natural disease and other microscopic findings such as asbestos bodies in the lungs or gunpowder particles around a gunshot wound. The pathologist also Collects and interprets toxicological analyses on bodily tissues and fluids to determine the chemical cause of accidental overdoses or deliberate poisonings. Forensic pathologists also work closely with the medico-legal authority for the area concerned with the investigation of sudden and unexpected deaths.
In the practice of forensic pathology, all of the disciplines of anatomic and clinical pathology, as well as other forensic sciences, are employed for the solution of medicolegal questions and cases. Cytological studies employing established methods of specimen collection and preparation are used for the determination of sex in both living and dead persons, for the determination of sex and for tissue identification in trace evidence and in the documentation of some disease processes occurring in the forensic setting.
Application of Forensic Pathology
Application of forensic pathology is involved in every forensic technique, since pathology is a step from where every evidence collection has to pass.
IV. Forensic Toxicology
Forensic toxicology is the use of toxicology and other disciplines such as analytical chemistry, pharmacology and clinical chemistry to aid medical or legal investigation of death, poisoning, and drug use. The primary concern for forensic toxicology is not the legal outcome of the toxicological investigation, but rather the technology and techniques for obtaining and interpreting the results. A toxicological analysis can be done to various kinds of samples. The first comprehensive work on forensic toxicology was published in 1813 by Mathieu Orifila. He was a respected Spanish chemist and the physician who is often given the distinction of "father of toxicology." His work emphasized the need for adequate proof of identification and the need for quality assurance. It also recognized the application of forensic toxicology in pharmaceutical, clinical, industrial and environmental fields.
A forensic toxicologist must consider the context of an investigation, in particular any physical symptoms recorded, and any evidence collected at a crime scene that may narrow the search, such as pill bottles, powders, trace residue, and any available chemicals. Provided with this information and samples with which to work, the forensic toxicologist must determine which toxic substances are present, in what concentrations, and the probable effect of those chemicals on the person. Determining the substance ingested is often complicated by the body's natural processes, as it is rare for a chemical to remain in its original form once in the body. For example: heroin is almost immediately metabolised into another substance and further to morphine, making detailed investigation into factors such as injection marks and chemical purity necessary to confirm diagnosis. The substance may also have been diluted by its dispersal through the body; while a pill or other regulated dose of a drug may have grams or milligrams of the active constituent, an individual sample under investigation may only contain micrograms or nanograms.
Some of the samples used in forensic toxicology are as below:
Urine: A urine sample is quick and easy for a live subject, and is common among drug testing for employees and athletes. Urine samples do not necessarily reflect the toxic substance the subject was influenced by at the time of the sample collection. An example of this is THC from cannabinoid (for example, marijuana) use, which in heavy users can be detected in urine for up to 14 days following use. Note also that it can take as long as 8 hours until a given substance can be detected. Specific to workplace drug testing, urine collection must be directly observed due to the prevalence of substance abusers "beating the test" via sample substitution or adulteration.
Blood: A blood sample of approximately 10 cm³ is usually sufficient to screen and confirm most common toxic substances. A blood sample provides the toxicologist with a profile of the substance that the subject was influenced by at the time of collection; for this reason, it is the sample of choice for measuring blood alcohol content in drunken driving cases.
Hair sample: Hair is capable of recording medium to long-term or high dosage substance abuse. Chemicals in the bloodstream may be transferred to the growing hair and stored in the follicle, providing a rough timeline of drug intake events. Head hair grows at rate of approximately 1 to 1.5 cm a month, and so cross sections from different sections of the follicle can give estimates as to when a substance was ingested. Testing for drugs in hair is not standard throughout the population. The dark and coarser the hair is the more drugs that will be found in the hair. If two people consumed the same amount of drugs, the person with the darker and coarser hair will have more drugs in their hair than the lighter haired person when tested. This raises issues of possible racial bias in substance tests with hair samples.
Oral fluid: Oral fluid is the proper term, however saliva is used commonly. Saliva is a component of oral fluid. Oral fluid is composed of many things and concentrations of drugs typically parallel to those found in blood. Sometimes referred to as ultra filtrate of blood, it is thought that drugs pass into oral fluid predominantly through a process known as passive diffusion. Drugs and pharmaceuticals that are highly protein bound in blood will have a lower concentration in oral fluid. The use of oral fluid is gaining importance in forensic toxicology for showing recent drug use, e.g. in clinical settings or investigation of driving under influence of substances.
Other bodily fluids and organs: Other bodily fluids and organs may provide samples, particularly samples collected during an autopsy. A common autopsy sample is the gastric contents of the deceased, which can be useful for detecting undigested pills or liquids that were ingested prior to death. In highly decomposed bodies, traditional samples may no longer be available. The vitreous humour from the eye may be used, as the fibrous layer of the eyeball and the eye socket of the skull protects the sample from trauma and adulteration. Other common organs used for toxicology are the brain, liver, spleen and stomach contents.
The inspection of the contents of the stomach must be part of every postmortem examination if possible because it may provide qualitative information concerning the nature of the last meal and the presence of abnormal constituents. Using it as a guide to the time of death, however, is theoretically unsound and presents many practical difficulties, although it may have limited applicability in some exceptional instances. Generally, using stomach contents as a guide to time of death involves an unacceptable degree of imprecision and is thus liable to mislead the investigator and the court.
Applications of Forensic Toxicology
Currently, this area of forensics has evolved to mean the study of illegal drugs and legal ones such as alcohol. Forensic toxicology can even identify poisons and hazardous chemicals. The chemical makeup of each substance is studied and they are also identified from different sources such as urine or hair. Forensic toxicology deals with the way that substances are absorbed, distributed or eliminated in the body the metabolism of substances. When learning about drugs and how they act in the body, forensic toxicology will study where the drug affects the body and how this occurs.
While there are many uses for forensic toxicology testing, the most familiar one to most people is likely to be drug and alcohol testing. This type of testing is commonly performed in the transportation industry and in workplaces. Another use is for drug overdoses, whether these are intended or accidental. People who drive with a blood alcohol concentration over the accepted legal limit can also be assessed through toxicology testing. Another application of forensic toxicology relates to sexual assault that involves the use of drugs. Various drugs are used today for the purposes of rendering the victim unable to fight the attacker, who then proceeds to sexually assault the victim. Through toxicology testing, a victim can find out what drug was given and can then be treated accordingly.
There are a lot of substances and poisons in our world many of which impact how we function in work and society. For some people, these substances can influence their death. Fortunately, forensic toxicology testing allows forensic scientists to identify substances and determine a pattern of use. In this way, a forensic toxicologist can provide closure on the 'what if' of a person's drug habits or perhaps some mystery surrounding their death.
LAW GOVERNING FORENSICS IN INDIA
Law governing expert evidence consists of:
(1) Enacted laws.
(2) Case laws.
(3) Court conventions.
Enacted laws
The main legal provisions, which govern the expert evidences, are in:
v Indian Constitution. (Article 20 (3) )
v Indian Evidence Act, 1872. ( Sections 45 & 112)
v Code of Criminal Procedure, 1972. ( Sections 53, 194 & 293)
v Identification of Prisoners Act.
In so far as the Indian legal system and its position is concerned, when Indian Evidence Act 1872 or the Code of Criminal Procedure, 1973 were enacted, legislature could not anticipate the tremendous development of modern science and technology and its deep impact on the forensic science as well as well as administration of justice. Neither the Indian Evidence Act nor the Code of Criminal Procedure has provisions to manage science and technology issues effectively since the rules of our judicial system lies on the bedrock of traditional law. There is no specific or special DNA legislation in India.
For collection of blood samples S. 53 of the CrPC is required which goes with the marginal heading Examination of the accused by Medical Practitioner at the request of the Police. This section deals with examination of the accused by a medical practitioner at the request of the police officer, if there are reasonable grounds for believing that an examination of a person will afford evidence as to the commission of offence. So it shall be lawful for a registered medical practitioner at the request of the police officer not below the rank of sub-inspector and for any person acting in good faith in his aid and under his direction, to make such an examination of the person arrested as is reasonably necessary in order to ascertain the facts which may afford such evidence and to use such force as is reasonably necessary. This section does not specifically say whether it would be applicable for DNA tests also. This section does not state that the police officer shall be entitled to personally collect semen, blood, hair root, urine, vaginal swab, etc for the purpose of investigation himself. By the amendment Act of 2005 the CrPC has been amended and added S. 53A which states that examination of a person accused of rape by medical practitioner. By the amendment act of 2005 the new Explanation now stands which include within its ambit examination of blood, blood stains, semen, sputum, swabs, sweat , hair samples and finger nails by the use of modern techniques in the case of sexual offences including DNA profiling and such other tests which is necessary in a particular case. Though, S. 53 of CrPC refers only to examination of the accused by medical practitioner at the request of the public officer but the Court has wider power for the purpose of doing justice in criminal cases. By issuing direction to the police officer to collect blood samples from the accused and conduct DNA test for the purpose of further investigation under S. 173(8) of CrPC. S. 293 (4) (e) of the CrPC provides for report of certain Government scientific experts. This section is only an ancillary provision which provides for giving of report by scientific experts.
Neither S. 53A, the amended S. 53A nor S. 164A of the CrPC are adequate to protect the interest of the suspects as well as the accused. Moreover the application of S. 53A and 164A is restricted to rape cases.
S. 112 of the Evidence Act raises a conclusive presumption about the paternity of a child born during the subsistence of a valid marriage. The said conclusiveness can be rebutted and it can be shown that the parties had no access to each other at the time when the child could have been begotten. The result of genuine DNA test is said to be scientifically accurate. If a husband and wife were living together during the time of conception, and the DNA test revealed that the child was not born to the husband, the conclusiveness in law would remain unrebuttable. There was an admitted access between husband and wife during which she could have conceived and delivered normal child. The presumption under s. 112 was not rebutted. No adverse inference can be drawn against refusing to submit himself to blood test. Section 112 requires the party disputing the paternity to prove non-access in order to dispel the presumption. “Access” and “non-access” mean the existence or non-existence of opportunities for the sexual intercourse. It does not mean actual co-habitation. It is a rebuttable presumption of law under s. 112 that a child born during the lawful wedlock is legitimate, and that access occurred between the parents. This presumption can only be displaced by a strong preponderance of evidence and not by a mere balance of probabilities.
EXPERT WITNESS
An expert witness or professional witness is an expert, who by virtue of education, training, skill, or experience, is believed to have expertise and specialised knowledge in a particular subject beyond that of the average person, sufficient that others may officially and legally rely upon the witness's specialized (scientific, technical or other) opinion about an evidence or fact issue within the scope of his expertise, referred to as the expert opinion, as an assistance to the fact-finder. Expert witnesses may also deliver expert evidence about facts from the domain of their expertise. Expert witnesses are usually instructed to produce a joint statement detailing points of agreement and disagreement to assist the court or tribunal. The meeting is held quite independently of instructing lawyers, and often assists in resolution of a case, especially if the experts review and modify their opinions. When this happens, substantial trial costs can be saved when the parties to a dispute agree to a settlement. In most systems, the trial (or the procedure) can be suspended in order to allow the experts to study the case and produce their results. More frequently, meetings of experts occur before trial. In forensic science there are forensic expert, who have skilled knowledge to analyse the evidences and give exact reasoning.
Science by definition is exact, uniform and variable, and scientific inferences are logically unimpeachable. Therefore scientific evidences can not be brushed aside. The only way available to disregard a scientific finding or the testimony of an expert witness is to show by cogent reason that either the scientific finding in question has no relevance with respect to the issue in question or the conclusions arrived at by the expert witness are not based on scientific reasoning but on speculations, or that the scientific process is not reliable for want of consistency.
SOME CRIMINAL CASES SOLVED BY FORENSICS ( INDIA)
Tandoor Murder Case (1995) Delhi
This was the first criminal case in India solved by the help of forensics. In this case Shusil Sharma murdered his wife at home by firing three bullets in to his wife Naina Sahni’s body. He killed his wife believing that she had her love affair with her classmate and fellow congress worker Matloob Karim. After murdering his wife Sharma took her body in his car to the Bagiya restaurant, where he and restaurant manager Keshav Kumar attempted to burn her in a tandoor there. Police recovered Sharma’s revolver and blood-stained clothes and sent them to Lodhi Road forensic laboratory. They also took blood sample of Sahni's parents, Harbhajan Singh and Jaswant Kaur and sent them to Hyderabad for a DNA test. According to the lab report, "Blood sample preserved by the doctor while conducting the post mortem and the blood stains on two leads recovered from the skull and the neck of the body of deceased Naina are of 'B' blood group." Confirming that the body was that of Sahni, the DNA report said, "The tests prove beyond any reasonable doubt that the charred body is that of Naina Sahni who is the biological offspring of Mr. Harbhajan Singh and Jaswant Kaur." And finally Mr. Shusil Sharma was found guilty with the help of forensic evidences.
Sister Abhaya murder case (1995) Kerala
The Sister Abhaya Case is a case regarding the death of a Knanaya Roman Catholic nun, who was found dead in a water well in St Pius X convent in Kottayam, India, on 27 March 1992. She was 19 years old at the time of her death and was a member of St. Joseph's Congregation for women under the Knanaya Catholic diocese of Kottayam, Kerala in India. She was a pre-degree student of BCM College, Kottayam and was staying in St Pius X Convent/Hostel at the time of her death. On the day of her death she got up from sleep early at around 4 am to study for her exam, had gone down to the kitchen of the hostel to get water from the refrigerator. Later her body was found in the well outside the kitchen in the convent/hostel compound. Scientific investigation methods such as polygraph tests, brain mapping/brain fingerprinting and narco analysis were used to solve the case. Subsequently two fathers of the church were arrested.
Aarushi Talwar murder case (2007) Noida
On the morning of May 16, 2008, Aarushi Talwar (May 24, 1993 - May 15, 2008), the 14-year-old daughter of a successful dentist couple, was found dead with her throat slit in her parents' home at Jalvayu Vihar in Noida, a posh suburb of Delhi. Suspicion immediately fell on the family's live-in man-servant, Yam Prasad Banjade alias Hemraj, a 45 year old Nepalese national, who was found missing from the home. Immediately declaring Hemraj as the prime suspect, the Noida police announced a reward for information leading to Hemraj's apprehension and arrest. In addition, a police party was dispatched to his hometown in Nepal, in hopes of apprehending him there. In this case fingerprinting was applied and DNA was extracted from the clothes containing blood stains. Also several fingerprints were found on the glasses of the house at the time of murder. Several narco analysis tests were applies on Aarushi’s father on CBI’s suspicion, but after no evidence Aarushi’s father was acquitted. The final verdict of the Court on this case is still pending.
Dinesh Dalmia v. C.B.I (2007)
The Central Bureau of Investigation (CBI) lodged a first information report against the appellant and three companies registered and incorporated under the Companies Act, 1956 on a complaint made by the Securities and Exchange Board of India. Indisputably, Appellant was named therein. He was, however, evading arrest. He had gone to the United States. The learned Magistrate by an order dated 14.02.2005, on a prayer made in that behalf by the CBI, issued a non-bailable warrant of arrest against him. Upon completion of investigation, a charge sheet was submitted before the Magistrate in terms of Sub-section (2) of Section 173 of the Code.
Investigation has revealed that Sh. Dinesh Dalmia, the then Managing Director & Custodian of properties, including shares, of M/s. DSQ Software Ltd., fraudulently got dematerialized un- allotted and unlisted share of DSQ Software Ltd. In the name of three entities namely New Vision Investment Ltd., UK; Dinesh Dalmia Technology Trust and Dr. Suryanil Ghosh, Trustee - Softechh Corporation and thereafter these shares were sold in the market and the proceeds of sale of said shares were credited in the accounts of M/s. DSQ Holdings Ltd., M/s. Hulda Properties and Trade Ltd. and M/s. Power flow Holding and Trading Pvt. Ltd. and thereby dishonestly misappropriated and cheated investors including existing share holders and obtained undue gain to the tune of Rs. 5,94,88,37,999/-. Thus, Sh. Dinesh Dalmia has committed fraudulent acts prima facie disclosing commission of offences of cheating, breach of trust, forgery and using forged documents as genuine by getting wrongful gain in the matter of partly paid shares.
This case is of our concerned because, in this case when Dalmia was arrested, and police requested the court for detention of Dalmia for more days until enough evidences had been collected in order to prove the charge. The court granted the detention and extended the days for collecting the evidences. Meanwhile the CBI introduced Dalmia to narco analysis test, in order to gain the truth behind the motive of crime, and at last they got some evidences in oral from Dalmia. But after the narco analysis test was introduced, several other issues regarding Fundamental Rights were raised by Dalmia; the first amongst them was, right to self incrimination, which is the major critique of these forensic tests. This case is not decided yet. This is a major critique of forensic science that, some times it does not stand true on testing.
CRITICISM
Forensic science is no doubt an advanced technique, which helps in delivering justice to the victim, in less time comparing to earlier criminal cases. Due to technological advancement in medical forensic science the evidence in criminal cases are discovered in a short span of time by collecting several biological samples like, blood, semen, skin, hair, saliva, teeth and many other biological samples. But sometimes forensic science fails to deliver justice, when a suspect is applied narco analysis, and other forensic tools and finally found not guilty of crime, then the rights of that person is violated. During many forensic tests a person provides knowledge of his relations, his privacy is violated at that moment, and also right to self incrimination is violated. In many cases in India and abroad a person is detained negligently by police and is subjected to forensic tests, which is injustice. We can take the case of Aarushi murder case, in this case the father of the deceased was detained and was subjected to many forensic tests like narco analysis, brain mapping, and finally he was acquitted. The right to dignity can be questioned for such instances where a suspect is not guilty and his privacy is hampered. The courts also had restricted the application of forensics in criminal cases if not required. In Dinesh’s Dalmia case also it was criticised that one accused cannot be a witness against himself, and the use of narco analysis test for reveling truth is unethical and construed as dangerous shortcut to investigation.
CONCLUSION
After completing my research in this project I have reached to a conclusion that, forensic science is a boon in delivery of justice without delay. Forensic science is a proved technique which involves several branches of science. Forensics consists of advanced modern medical technology. Forensics requires an expert who can collect biological samples paying essential precautions while their collection, like proper handling, proper storage of biological samples like blood, semen, saliva, hair etc. Forensic science still needs some technological advancement. Forensic science also requires experts in criminal cases, who can collect evidences safely. Unlike the practice in USA and England and other developing countries, DNA Technology has a very little application in the Indian Legal System. The admissibility of the DNA evidence before the Court always depends upon its accurate and proper collection, preservation and documentation by which the prosecution can be able to satisfy the court the unbroken chain of custody of the physical sample from the time of seizure to the time of analysis.
The modus operandi of the crime has become complex in the modern scientific era. It is essential that science and technology that are developed in the laboratories be applied in real life also. It must be converged with the laws too, especially with criminal Justice administration system. It is to be acknowledged that laws must not be static but dynamic in its approach and must be in harmony with the society. The trouble with the laws these days is that criminals are changing their strategies faster than the legislature. As in the famous words of Edmund Burke “Bad laws are the worst sort of tyranny” and if the tyranny is not controlled no one but the innocent will be destroyed and massacred. The development of DNA technology AHARAY furthers the search for truth by helping police and prosecutors in the fight against violent crime. Through the use of DNA evidence, prosecutors are able to conclusively establish the guilt of a defendant. So, the importance of DNA technology in the administration of Justice in any form of society and in any part of the world cannot be denied. India has already put a step forward in this approach by developing the DNA Drafting Bill 2007. The Bill is inspired from such DNA Legislations from around the globe. Though the Bill is yet to see the light of the day, but it can be said that first step has already been laid in the path of a specific Forensic legislation.
REFERENCES FOR FURTHER READINGS (WEBSITES)
I. http://insects.about.com/od/forensicentomology/f/CSItoxicology.htm
II. http://www.udel.edu/PR/UpDate/97/17/8.html
III. http://biologicalevidence.suite101.com/article.cfm/what_is_a_forensic_entomologist
IV. www.francesfarmersrevenge.com/stuff/serialkillers/boden.htm
V. http://ses.library.usyd.edu.au/bitstream/2123/669/4/adt-NU20051101.22492201front.pdf
VI. http://www.all-about-forensic-science.com/forensic-odontology.html
VII. http://pjms.com.pk/issues/janmar08/pdf/teeth.pdf
VIII. http://new.trutv.com/library/crime/serial_killers/notorious/bundy/14.html
IX. http://www.ncbi.nlm.nih.gov/pubmed/7018144
X. http://books.google.co.in/books?id=4VkXpNe9xLoC&dq=criminal+cases+solved+by+forensic+pathology&printsec=frontcover&source=in&hl=en&ei=2fVyS5CONs-IkAWr07CACg&sa=X&oi=book_result&ct=result&resnum=12&ved=0CC8Q6AEwCw#v=onepage&q=&f=false
XI. http://www.forensic-medecine.info/forensic-pathology.html
XII. http://www.exploreforensics.co.uk/forensic-toxicology.html
XIII. http://en.wikipedia.org/wiki/Sister_Abhaya_murder_case
XIV. http://www.santoshraut.com/forensic/forensicscinindia.htm
XV. www.forensicentomologyindia.com/
XVI. http://speakindia.wordpress.com/2008/07/16/arushi-talwar-murder-case-finally-solved/
BOOKS REFERRED
(1) Forensic Science in Criminal Investigation & Trials, B. R. Sharma, Fourth Edition, Universal Law Publications.
(2) Law Relating to Narcotic Drugs and Psychotropic Substances in India, R. P. Kataria, Second Edition, Orient Publications.
(3) Forensic Science in Criminal Investigation, Dr. Jai Shanker Singh, Unique Law Publications.
(4) Medical Jurisprudence and Toxicology, Moitra & Kaushal, Third Edition, Delight Publications.
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