Transcript
CHAPTER ONE LITERATURE REVIEW
1.1 Overview
In this chapter an explanation of history of forensic science and some of the most important incidents and crimes that helped the development of this science are presented. Explain the term of forensic dentistry and its importance, the problems that are faced in this kind of forensic science, the areas that could be used in. In this thesis we also explained the X-ray images and how it is captured. We also discuss usefulness of X-ray in various fields, especially in the field of identification of human remains and dead bodies.
1.2 Literature Background
Forensic science is the use of the scientific method in the examination and analysis of criminal evidence. To solve crimes it must using evidence that collected from crime scene, such as fingerprints, footprints, bite marks, blood, hair and Handwriting and typewriting samples are studied, including all ink, paper, and typography [6].
The ward forensic comes from the Latin forensis meaning (of or before forum). In Roman time, a criminal charge meant presenting the case in front of a group of public individual in the forum. Both the person accused of the crime and the accuser would give speeches based on their sides of the story. The individual with the best argument and delivery would determine the outcome of the case [7].
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.
1.3 Forensic History Timeline
The first forensic science recorded in 44 B.C. of Julius Caesar after his assassination at the theatre of Pompey Antistius, a Roman physician, later examined the body and discovered that while Caesar had been stabbed 23 times, only the second wound to the chest had been killed him [7].
In China, a Chinese doctor Song Ci (1248) had wrote a book that describes how using medicine and entomology to solve criminal cases. The name of his book is "Xi Yuan Ji Ln" (" collected cases of injustice rectified"). One of the cases in the book was the case of a person murdered with a sickle was solved by a death investigation who instructed everyone to bring his sickle to one location, then attracted by the small of blood eventually gathered one a single sickle, then the murderer confessed. The book also offered advice on how to distinguish between a drowning and strangulation along with other evidence from examining dead body on determining if a death was caused by murder, suicide or an accident [8].
In French, a French army surgeon Dr. Ambroise Pare (1547) wrote a book about the treatment of wounds by firearms and arrows. And before that he studies the effect of wiolent upon the internal organs. His work is seen as the beginning of modern forensic pathology.
In 1784 at Lancaster, England, John Toms was tried and convicted for murdering Edward Culshaw with a pistol. When the dead body of Clushaw was examined. A pistol wand ("crushed paper used to secure powder and bolls in the muzzle") founded in his head wound matched perfectly with a torn newspaper found in Toms packet, this is the first time using physical matching for forensic science [8].
Henry Goddard (1837), he is a member of the bow street runners, London (first professional police force) also used physical analysis to attempt to connect a bullet to a murder weapon. During a robbery investigation, Goddard noticed that one of the bullets used had a small defect left by a small hole in the mold. He surmised that if he could find the mold he could fined the thief and he was right, he found the mold in possession of the house butler who at once admitted to the robbery [8].
Few year later forensic toxicology uses often brought in to examine pieces of evidence such as the body or food, when the primary type of poison in use to killed was arsenic. And there were no reliable ways of testing for its presence, Mathieu Joseph Bonaventure Orfila (1840) created new techniques and refined existing techniques in his first book. Greatly enhancing their accuracy. In 1840, Marie LaFarge was tried for the murder of her husband using arsenic. Arsenic was found in the food, none could be found in the body. Orfila was asked by the court to investigate. He discovered that there was in fact arsenic in the body, allowing LaFarge to be found guilty [7].
Odelbrecht used photography for identification of criminal for a first time was in 1864 and the documentation of evidence and crime scenes.
L.W. Atcherley, a police officer in the West Riding Yorkshire constabulary in England, developed in 1883 a system for determining the killer modus operandi ("method of operation") by using different crime scenes to establish a pattern of behavior that indicates a common killer. The system consists of ten points. Scotland Yard later adopted several of Atcherley's techniques which are still in used to this time [9]. The ten point system consist of:
Place of the crime
Point of entry
Method of entry
Tools used during the criminal act
Kinds of objects removed from the scene of a crime
Time of day when the crime occurred
The culprit's alibi
The culprit's accomplices
Mode of transportation to and from the scene
Unusual characteristics of the crime, such as killing the house cat or leaving behind a note or object to challenge police.
In 1897 the first fingerprint official office opened in Calcutta, India after the council of the governor general approved report that fingerprints was unique for each person and no chance to be the same fingerprint for two person and should be used for classification of criminal record [7].
Dr. Edmond Locard founded the first laboratory dedicated to criminal investigation in 1910. Dr. Locard was known as the Sherloch Holmes of France. He formulates the basic principle science "Every contact leaves a trace", this becomes known as Locard's Exchange Principle [7] [8].
In 1924 Philip O. Gravelle, which developed comparison microscope for the identification of fired bullets and cartridge cases. It was a giant jump in firearms identification in forensic science. The firearm from which a bullet or cartridge case has been fired is recognized by the comparison between the signs of the unique formed on the bullet or cartridge case formed of metal and worn on the barrel, breach of black, extractor or firing pin in the gun or through any other sign is characterized by the bullet [7] [8].
August Vollmer chief of the Los Angles police, established the first American police crime laboratory in 1935 [7].
Even through using bite mark evidence begin around 1870, the first published account involving a conviction based on bite marks as evidence was in the case of Doule V. State which happened in Texas in 1945. The bite mark in this case was on a piece of cheese found at the crime scene of a robbery. The suspect was later asked to bite another piece of cheese for comparison. A firearm examiner and the dentists evaluate the bite marks independently and both concluded that the marks were made by the same set of teeth. The bite marks that found in crime scene on an object or skin used as evidence in future cases [7].
The deoxyribonucleic acid (DNA) profiling technique was first reported in 1985 by Sir Alec Jeffreys at the University of Leicester in England. And is new the basis of several national DNA databases [8].
In the spring 1997, The Criminal Justice Information Services division (CJIS) of the FBI created a dental task force (DTF) whose goal is to improve the utilization and effectiveness of the National Crime Information Center's (NCIC) Missing and Unidentified Persons (MUP) files [7].
1.4 Forensic Dentistry
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 marks analysis. The study of odontology in legal case can be a piece of incriminating evidence or an aspect of wide controversy [4].
One of the earliest known examples of forensic dentistry involved Agrippina, the mother of Roman emperor Nero. In 49 B.C. Agrippina ordered the death of her rival Lollia Paulina, who was in competition with her to be the wife of Emperor Claudius. Agrippina demanded to see Lollia Paulina's head as proof of the death, but she was not sure that her rival was dead until she noticed Lollia Paulina's distinctive discolored front teeth [4].
Another famous jump for the forensic dentistry was that of Paul Revere (1825), who besides being a blacksmith was also a dentist. He helped identify Revolutionary War dead who had been buried on the battlefield by their teeth and dental work. Revere was able to identify Dr. Joseph Warren, the man who sent him on his famous ride, because he had made him a partial out of silver wire and pieces of hippo tusk [4].
Dental identification of a body is necessary when visual identification is impossible and the deceased has no other from of identification on them. Extensive disfigurement or body decomposition is both situations when forensic dentistry is required.
There is no official dental database corresponds to databases of fingerprints or DNA, but in the other hand almost everyone who has visited a dentist has a record of their teeth, so dental records are how forensic scientists identify the dead. Tooth enamel (the outer layer of teeth) is harder than any other substance in the human body, which is the reason that makes the teeth remain long time after all other parts have decayed. Victims of fires are often identified by their teeth, which can hold temperatures of more than 2,000 degrees Fahrenheit (1,093 degrees Celsius). Dental work, such as a partial or gold crown, will be distorted by fire but can still aid in identification [4].
To identity people through their teeth, first thing the dentist must have a dental record or the record of the personal dentist record. In the case of the occurrence of the death of a collective like plane crash can forensic dentists access to a list of individuals and by comparing dental records that they have with the samples they found at the scene and try to find a possible match. Even with a few teeth remain this way able to identify and with high accuracy to deceased and get a positive result of the examination. The best kinds of comparisons come through X-rays, where they appear fillings, bridges, and any surgery that underwent before the death.
Identifying an individual by his/her teeth without dental records are much more difficult but may be the identification through things such as bridges, broken teeth, surgical, missing teeth or crowns of gold that can recognizes by family or friends or even the doctor.
In addition to dental records can be help the forensic investigators in the collecting samples of DNA extracted from the teeth pulp. The tooth pulp can be damaged by external factors not like the enamel tooth, however it still for hundreds of years [10].
Forensic dentists are responsible of the following areas of practice:
1. Identification of found human remains in cases of mass fatalities.
2. Help the investigator to identify the identity of the criminal through the dental evidence.
3. Sex determination
4. Age estimation.
5. Reconfiguration of he face features, used especially in the case of insufficient of dental evidence.
6. Identify of blood group through dental pulp
7. Establish paternity cases
8. Discovery of some cases of poisoning with oral manifestations.
1.5 Dental Radiograph
Dental radiographs commonly referred to X-ray films or informally X-ray. X-rays are picture of the teeth, bones and surrounding soft tissues to screen for and help identify problems with the teeth, mouth and jaw. X-ray picture can show, cancerous or benign masses, hidden dental structures (such as wisdom teeth), and bone loss that cannot be seen during a visual examination. Dental X-ray may also be done as follow-up after dental treatments.
A radiographic image is formed by a controlled burst of X-ray radiation which penetrates oral structure at different levels, depending on varying anatomical densities, because less radiation penetrates them to reach the film. Dental caries infections and other changes in the bone density, and the periodontal ligament, appear darker because X-ray readily penetrates these less dense structures.
Dental restorations (fillings, crowns) may appear lighter or darker depending on the density of the material as shown in figure 1.1.
Figure 1.1 Full Mouth Dental Radiography.
In some disasters, the investigators using X-ray machine for taking a radiography images to the teeth of the victims and comparing it with the available dental records to help the experts to get a possible matching to identify potential victims.
1.6 Summary
This chapter describes brief explanation of history of forensic science and some of the most important incidents and crimes that helped the development of this science. Explaining the term of forensic dentistry and its importance. The problems that facing this kind of forensic science, the areas that could be used in. Then explaining the X-rays and how it is captured. It's useful in various fields, especially in the field of identification of human remains and dead bodies. The next chapter will be an introduction to Artificial Neural Networks approaches and applications.
