Bitemark History
In struggles in the middle of assailants and victims, there is a tendency for teeth to be used as a weapon. Sometimes it is the only defensive tactic for a victim to impose serious injury on the assailant. It is a well known fact, that in sexual attacks together with sexual homicide, rape and child sexual abuse, the assailants more often than not bite their victims. This can be viewed as an expression of dominance, rage and animalistic behaviour. Not many citizen have the view that teeth can be such violent weapons (Sweet & Pretty, 2001).
Early recognition of bite marks is seen in old English Law where 'member permissible for defence; included arms, legs and former teeth'. The first bite mark case in the United States was the supreme Salem Witch Trials, in 1692. Rev. Burroughs who was convicted and hanged used to bite his victims. While the trial his bite marks and of other citizen were compared to the victim's marks. The judges facilely acceptable the bite marks as evidence. In 1870, A.I Robinson was suspected of murdering his mistress. Five bite marks were found on her arm. The bite mark evidence did not hold and Robinson was acquitted. Despite the negative outcome of the Robinson case, by 1890 bite mark evidence started to be recognized in scientific circles (Vale as cited Dorion, 2004).
Prior to 1950, the estimate of cases where bite marks were used as evidence was small when compared to today. A large proportion was reported in Europe and Japan, but most cases originated in the Usa. In 2002, over 400 forensic odontologists were listed in the American Academy of Forensic Sciences (Aafs) (Dorion, 2004).
A major development in bite mark investigations in the Usa began in 1962 when courses in forensic odontolgy began at the Armed soldiery institute of analysis (Afip) in Washington D.C. The development of forensic odontology was furthered by the publication of a book in 1966 by Gustafson, called 'Forensic Odontology'. This book had a stupendous chapter devoted to bite marks and was the first major work to be published on this subject. Then in 1970, forensic odontology became a department in the Aafs, and became recognized as a specialty in forensic science. In 1976, the American Board of Forensic Odontology (Abfo) was organized. This was a step towards professionalism in the sector of forensic odontology. The Abfo started to furnish a programme of certification in forensic odontology. This furthered the science of forensic odontology and made it more reliable (Dorion, 2004).
Forensic Odontologists
A forensic dentist is not an commonplace dentist; s/he is a board- certified devotee who deals primarily with bite mark evidence. Although, one does not have to be a devotee to become an devotee witness, it helps to advance the validity of the scientific evidence in court (O'Conner, 2006).
Forensic odontolgy is a field of forensic rehabilitation that in the interest of justice deals with dental evidence presented in the courts of law. The work of a forensic odontologist is to identify human remains straight through dental records, estimation age of both living and deceased persons, analysis of bite marks on victims and other substances such as foodstuffs and presentation of bite mark evidence in court as an devotee witness (Sellar, 2002).
Human Bite Marks
Of all the components of the human body teeth outlast all other parts after death. Their durableness makes it excellent for identification. Sometimes, they are the only means of identification left. A clear example is Adolf Hitler's dental records, which identified his corpse. It is claimed that no two citizen have same teeth. Unlike fingerprints which remain unchanged, teeth become unique with wear and tear. For prosperous identification both ante and post mortem data should be available, even one tooth can be beneficial for identification (Evans, 2004).
There are about two hundred separate tooth charting methods in the world, which furnish an roughly 100 % reliable means of identification. The American approach, which is known as the Universal system, gives a estimate to each of the thirty two adult teeth. Facts is then recorded on each tooth according to the five graphic exterior of the tooth. With this information, the odontologists can faultless a dental grid, unique to that person (Evans, 2004).
Human bite marks are found when teeth are used as weapons. They can be used as weapons of anger; weapons of excitement; weapons of control or weapons of destruction (Lotter, 2008). Bite marks are usually found on the skin of the victim. Females are usually bitten on the breasts and legs While sexual attacks, while men are usually bitten on the arms or shoulders and when in defensive postures bites can be found on the hands and arms (Sweet & Pretty, 2001).
The marks left by the teeth in a person may be used to identify an individual. Nowadays forensic odontologists have become reasonably skilled at identifying bite marks and relating it back to the person who has inflicted the mark (Horswell, 2004). A human bite mark is usually described as an elliptical or circular injury and the differences in size and shape of teeth can sometimes be literally noticed especially when teeth are missing or important (Lotter, 2008). However, a bite mark is not an widespread correct representation of the teeth; it also depends on the jaw movement and use of the tongue. The lower jaw is moveable and is the one that gives the most biting force, while the upper jaw is usually writing materials and holds and stretches the skin (Evans, 2004). The most tasteless type of bite marks are contusions. Incisions offer the best three dimensional images of the teeth. If avulsions and artefacts are combined, one can produce a three dimensional image too. There are seven types of bite marks; haemorrhage which is a small bleeding spot, abrasion which is an undamaging mark on skin, contusion which is a ruptured blood vessel bruise, laceration which is punctured or torn skin, avulsion were there is discharge of the skin and artefact were a piece of the body is bitten off. These are then additional divided into four degrees of impression, which when analysed can help to note what kind of violence was exerted and may be used as aggravating circumstances.
1. Valuable pressure
2. First degree pressure
3. Violent pressure
4. Skin violently torn from body
(O'Conner, 2006).
Bite Mark Analysis
In odontology, for a corporeal comparison of a bite mark to be successful, the questioned evidence (Q) photo of the bite mark must be accurately produced. It must then be recreated in a life size dimension, and is then called the Known (K) evidence. After this is done, the plaster cast of the defendant's teeth are used to identify any similarities in shape, positioning and so on and forth (Bowers & Johansen, 2004). The methods typically used include the older ones for example hand tracing the teeth perimeters on clear acetate, then Xeroxing the dental casts and then tracing them on acetate too. The dental cast teeth are then pushed into wax and filled thereafter with metallic powder. After this is done an x-ray film is used to capture the teeth impression. The direct superimposition of Q and K photographs are used when dentists testify in court, to show that there is sufficient identification value to reach a result. These are all meticulously made to scale to be able to furnish truthful and correct comparison results (Bowers & Johansen, 2004).
Recently, digital imaging software and image capture devices have created a more developed and correct way to avoid any discrepancies and allows the interpreter to use the computer functions into a microscope for comparison. The computerized ideas of analyzing bite marks has the benefits of creating correct means of measuring corporeal parameters of crime scene evidence, corrects tasteless photographic distortion and size discrepancies, helps to eliminate any interpreter subjectivity, betters the control of image visualization, standardizes comparison procedures, helps to create reproducibility of results in the middle of separate examiners and is ideal for electronic transmission and archiving (Bowers & Johansen, 2004). The good the bite mark, the good an devotee can make a reliable comparison (O' Connor, 2006).
The American Board of Forensic Odontology (Abfo) follows bite mark standards and guidelines. The Abfo provides a list of commonly acceptable methods that meet the criteria of the scientific model. This is to help forensic odontology to perform the objective of universally acceptable methodology. The Abfo provides guidance on how to hold bite mark evidence, which are saliva swabs of bite site, photographic documentation of the bite site which includes lighting and scale, obtaining impressions of bite site together with victim's dental impressions, tissue specimens. Guidelines are also formulated on the evidence variety of suspected dentition and these include the photographic documentation of the dentition, clinical exam with extraoral and intraoral considerations and dental impressions. In 1994 the Abfo indicated that the most widely used methods of comparing bite mark evidence were; the generation of overlays (acetate), test bite media such as wax exemplars, Styrofoam and so on and comparison techniques mostly using acetate.
All Abfo diplomats are unbelievable to use the most analytical standards and methods suggested. distinct vital Facts must all the time be recorded and noted. These are done both in the case of a living victim as a deceased individual. Demographics include details such as name of victim, case estimate and date of examination, person to contact, age of victim, sex and name of examiner. The location of bite mark, which includes the anatomical location, report of exterior contour and whether it is flat, curved or irregular and a report of the tissue characteristics with details on the basic bone, cartilage, muscle and fat buildings and if the skin is fixed or mobile. The shape of the bite mark must be described for example if it is round, ovoid, crescent, irregular etc. The colour of the bite mark is also important to note, e.g. Red, purple.
The size is also to be noted, whether it is vertical or horizontal and preferably noted in the metric system. The injury can be a petechial hemorrhage, contusion, abrasion, laceration, incision, avulsion or artifact. Other Facts that is to be gathered if inherent is whether the skin exterior of indented or level (Bowers & Johansen, 2004). Since the skin is elastic, and depending on the victim some bite marks may last for hours while others may last for days. All bite marks alter themselves as time elapses, therefore it is important to photo the bite marks as consistent intervals over a duration of hours and days as recommended by the Abfo (O'Connor, 2006).
Bite Marks And Criminal Justice System
The criminal justice ideas has long endorsed odontology as a major source of Valuable aid. Apart from identifying perpetrators of crime, odontology has also helped in the identification of unidentified persons (Fbi Laboratory, 1989 as cited in Brennan, Gray- Ray, & Hensley, 1997).
Differences in teeth are as separate as those marks found by other tools and fingerprints. Though a person's teeth may look the same, they are separate in size, shape, arrangement, wear, damage, age, quality and quantity and habits of the private (Levine, 1972 ac cited in Brennan, Gray- Ray, & Hensley, 1997). The Fbi Laboratory in 1989 has finished that dental uniqueness is beyond any cheap doubt.
Bite mark analysis and evidence has been judicially acceptable in the United States since 1954 (Doyle vs. State). It was only in 1975, that bite mark evidence gave us the Marx acceptable of admissibility (People vs. Marx, 1975). The identification of a biter has been beneficial and instrumental in criminal investigations especially in cases of homicide; sexual abuse and child abuse cases (Pretty & Sweet, 2000 as cited in Bowers & Johansen, 2001). The Usa has quite a developed ideas of dental records based on the Universal ideas and this helps considerably especially in identifying 'John/ Jane Doe' victims (O'Connor, 2006).
The forensic weight and value of the bite mark is based on the characteristics of the bite marks that are similar to the defendant's. Most dentists' though, rely on a 'rule in' or 'rule out' fashion and therefore furnish a weak linkage. So at this stage, the forensic weight of this evidence can be argued (Bowers & Johansen, 2004).
Forensic odontology is still new to criminal justice officials and its success in the criminal justice field has never been researched as yet. In the meantime two important experts in the field, Dr. Haynes and Dr. West have been doing well by using ultra violet lighting to detect human bite marks on rape victims. With this formula they have helped to capture and convict ten rapists. Bite marks in the investigation and prosecution of rapists is vital, since many rapists bite their victims. Bite mark evidence can be as conclusive as both Dna and fingerprint evidence in the case of rape. Valuable Facts can be obtained from the analysis of the bite mark. Odontology has proved to be exceptionally correct in violent rape cases, since bite marks are mostly present in violent rape cases (Haynes and West, 1992 as cited in Brennan, Gray- Ray, & Hensley, 1997).
It must be kept in mind that bite marks are not little to skin. Teeth leave impressions on a estimate of things and if these are found at the crime scene they can help in the investigation, for e.g. A piece of chewing gum or food like cheese or chocolate (Geberth, 2006). As far back as 1906 in the Uk, two burglars were convicted after one of them bit a piece of cheese which was found on the crime scene. The prosecutors then showed that imprint matched exactly his front teeth (Evans, 2004).
The quality of the corporeal evidence, the changeable nature of skin bruising and the inability of dentists to accurately and scientifically prove that teeth are unique, create problems in the estimation of distinct identification to be used in court (Bowers, 2004). Legal challenges for bite mark evidence are usually two: reliability of analysis and whether it violates constitutional possession (Stimson & Mertz, 1997).
Though there are strong arguments that hold that each human has a unique dental profile and is discernable in bite marks this has not been proven valid by any experiments and thus causes serious problems when presenting bite mark evidence in the courts of justice. The estimate and degree of detail of the bite mark may vary from case to case and if it is assumed that human dentition is unique it is sufficient to use as forensic evidence. In the case where it is not known whether this individuality is specific, the most a bite mark can do is to exclude or include a person, as bite mark evidence is not sufficient to get a conviction (Bowers, 2004). More investigate is needed to prove beyond doubt that each human dentition is unique (Sweet & Pretty, 2001).
Other problems that are encountered with devotee witnesses in court are that it is high unlikely that their qualifications will ever be challenged on stand and most of the time odontologists work only on a part time basis with a law compulsion agency. Another issue is the question if a acceptable protocol. In this single field, specialists tend to use their own methods. There is also the digital divide, while others use the older methods (acetate). When comparing results this causes difficulties since the methods used are not the same and therefore blind reviews reflect poorly on the professionalism of odontologists (O'Connor, 2006).
Famous Bitemark Evidence Cases
The most supreme case where bite mark evidence led to a conviction is without fail the case of the serial killer Ted Bundy. Nowadays when referring to bite mark evidence, citizen still talk about the Bundy case. Bundy was never caught until the devotee testimony of Dr. Sauviron secured a conviction and subsequent execution. In the trial, photographic evidence of the bite marks and Bundy's teeth were shown. The acetate of the bite mark was then located over the photo of Bundy's teeth leaving no doubt whose teeth had left the impression.
Nobody is distinct how many citizen Bundy killed in the middle of 1973 and 1978, but he was finally convicted for the murder of Lisa Levy of Florida. This was done because of the bites that were found on her body. Forensic bite mark analysis showed beyond doubt that the impressions were left by Bundy's irregular teeth (Lotter, 2008).
There were other cases were men were unfortunately convicted because of erroneous bite mark identification evidence. Ray Krone was jailed for ten years for a crime he had not committed. A waitress, in Phoenix was murdered in 1991 and Krone was sentenced for her murder. After Dna testing was done, Krone was free and the true perpetrator was identified. Forensic Dna was not ready at the time of the prosecution and only a bite mark found on the victim's breast associated Krone to the murder. Even though the evidence was very weak, he was convicted because of the bite mark a forensic odontologist had said matched the dentition of Krone. After an appeal, the tank top the victim was wearing was re examined and salvia was found that did not belong to Krone (Unknown Author, 2008). In 1992, Roy Brown was convicted of stabbing, beating, biting and strangling a communal laborer in New York. The case rested on one piece of evidence, a bite mark. A local dentist testified that they matched Brown's teeth. He has been released in January 2007. Dna testing has proved that the saliva left in the bite mark did not match Brown's. Other inconsistencies were that Brown has two missing front teeth, but the devotee testified that these could have been filled by twisting the skin (Santos, 2007).
Unfortunately there were cases were the prosecution used bite mark evidence to get convictions, even if the person was innocent. With Dna and other evidence becoming more widely available, most cases have been overturned where justice had not been served. Bite mark evidence must be used considered and the over zealousness of prosecutors in acquiring a conviction must not interfere with evidence. In fact, in 1995 forensic odontologists have started to avoid using the term 'match' to eliminate errors, since other evidence should be produced together with bite marks (Santos, 2007). Csi effects on the normal communal has exaggerated the accurateness of bite mark evidence. Bite mark evidence can resolve whether a field can be excluded or whether the surmise could be the one who inflicted the bite. More investigate is needed since bite mark evidence on its own does not all the time produce conclusive results.
Bite Mark Forensic Evidence