The above link is to all of the info about the Alaskan Airline crash. Scroll down to the part where people really blast DMORT. Then,
go to the last section and read the suggestions on how to improve mass fatality operations. Very interesting and - unusual reading.
The above link isn't required for homework, but you might find it interesting.
Human Bite Marks
This guide tells you all about human bite marks. It explains how bite marks are recognized and gives details of
evidence collection techniques and how to analyze the injuries.
Teeth are often used as weapons when one person attacks another or when a victim tries to ward off an
assailant. It is relatively simple to record the evidence from the injury and the teeth for comparison of the
shapes, sizes and pattern that are present. However, this comparative analysis is often very difficult, especially
since human skin is curved, elastic, distortable and undergoing edema (swelling).
In many cases, though, conclusions can be reached about any role a suspect may have played in a crime.
Additionally, traces of saliva deposited during biting can be recovered to acquire DNA evidence and this can be
analyzed to determine who contributed this biological evidence. If dentists are aware of the various methods to
collect and preserve bite mark evidence from victims and suspects it may be possible for them to assist the
justice system to identify and prosecute violent offenders. This paper reviews the recognition and recovery of
this evidence and provides insight into modern methods used to investigate bite mark evidence from heinous
In mortal combat situations, such as the violence associated with life and death struggles between assailants
and victims, the teeth are often used as a weapon. Indeed, using the teeth to inflict serious injury on an attacker
may be the only available defensive method for a victim. Alternatively, it is well known that assailants in sexual
attacks or abuse, often bite their victims as an expression of dominance, rage and animalistic behavior.
The teeth are a significant component of our natural arsenal. It is suspected that many dentists have seldom
considered their patients' teeth as such effective weapons! The aim of this paper is to provide information
about this form of forensic evidence and to demonstrate how human bite marks are used by courts
to answer important questions that may arise during the prosecution of accused suspects.
Currently, there is no agreement among forensic odontologists about the individuality (uniqueness)
of the dentition or the behavior of human skin during biting.
Much research is currently underway in an attempt to prove the suspicion that each human dentition is unique.
The sizes, shapes and pattern of the biting edges of the anterior teeth that are arranged in the upper and lower
dental arcades are thought to be specific to that individual from the way the teeth are arranged in the mouth.
The resulting configuration of the dentition produces an identifiable pattern that may be compared with similar
patterns found on bitten objects to determine the likelihood that a specific individual has left their calling card.
The amount and degree of detail recorded in the bitten surface may vary from case to case. In
situations where sufficient detail is available, it may be possible to identify the biter to the exclusion
of all others. Perhaps more significantly, it is possible to exclude suspects that did not leave the
Typical presentation of bite mark injuries
Human bite marks are most often found on the skin of victims, and they may be found on almost all parts of the
human body. In defensive circumstances, as when the arms are held up to ward off an attacker, the arms and
hands are often bitten.
A representative human bite is described as an elliptical or circular injury that records the specific
characteristics of the teeth. The injury may be shaped like a doughnut with characteristics recorded
around the perimeter of the mark.
Alternatively, it may be composed of two U-shaped arches that are separated at their bases by an open space.
The diameter of the injury typically ranges from 25-40 mm.
Often a central area of bruising can be seen within the marks from the teeth. This bleeding is caused by
pressure from the teeth as they compress the tissue inward from the perimeter of the mark.
bite marks with high evidentiary value that can be used in comparisons with the suspects' teeth will
include marks from specific teeth that accurately record distinct traits. It is possible to identify
specific types of teeth by their class characteristics.
For example, incisors produce rectangular injuries and canines produce triangular injuries. But it is
necessary to have individual characteristics recorded in the bite mark to be able to identify
positively the perpetrator. Use, misuse and abuse of the teeth result in unique features that are
referred to as accidental or individual traits. When these are recorded in the injury it may be
possible to compare them to identify the specific teeth (person) that caused the injury.
If these individual characteristics are not present in the teeth, or if they are not recorded well in the injury, the
overall forensic significance of the bite mark is reduced.
The injuries caused by teeth can range from bruises to scrapes and cuts or lacerations. Certainly, it is possible
for enough force to be generated to allow penetration of the biting edges of the teeth into the deep layers of the
skin. If much time elapses from the moment of injury to the time of discovery, bruises and the
changes associated with injuries over time may further diminish the evidence value. This is
especially true in the case of living bite victims but also in deceased individuals.
Evidence collection from the bite victim
The dentist in private general practice does not often have the opportunity to deal with procedures for collecting
evidence from bite victims. Detectives at the scene of the crime, pathologists at autopsy or medical personnel in
the emergency suite find most bites.
But since physical and biological evidence from a bite mark begins to deteriorate soon after the bite
is inflicted, all dentists should be familiar with the general principles of evidence collection.
This is especially true for dentists that deal with patient populations that may potentially contain victims of
domestic violence, in which bites are often discovered.
Practitioners should make every effort to accurately and precisely preserve the evidence as soon as it is
discovered using the following techniques, and not wait until others with more experience can be consulted or
summoned. The best or only opportunity to collect the evidence may be when it is first presented and observed.
If a dentist finds a patterned injury that is suspected to be a bite mark, it should be reported to the police or
social welfare agency with local jurisdiction. Then, the dentist should complete the following list of procedures to
properly collect the evidence:
Make a record of the injury, including descriptive, narrative notes that document the physical appearance,
colour, size and orientation of the injury. What is the location on the body? What is the relative contour and
elasticity of the site? Can the difference between marks from the upper and lower teeth be determined? What
types of injuries are present? Cuts? Bruises? Scrapes?
Take extensive orientation and close-up photographs with both colour and black-and-white film. A reference
scale, such as a ruler, should be placed in the same plane as the injury and visible in the photographs to enable
subsequent measurements. Be certain that the camera is positioned directly over the injury site. The long axis
of the lens should be perpendicular to the bitten skin to reduce perspective distortion in the photographs.
Fabricate an accurate impression of the bitten surface to record any irregularities produced by the teeth, such
as cuts, abrasions, etc.
Prompt medical attention should be provided for the living victim since human bites have a higher potential for
infection than animal bites. Injuries that disrupt the integrity of the skin's surface should be treated as soon as
Evidence collection from the bite suspect - Read this carefully - Mrs. B.
The collection of dental exhibits for forensic uses has been deemed to be an invasive procedure.
Thus, dental impressions and bite samples that are seized from a suspect are susceptible to strict
rules of evidence. They must be obtained either using a court order (warrant) or with a signed and
witnessed informed consent. North American Courts have ruled that collection of this type of
evidence does not violate the individual's rights against self-incrimination because he is not being
required to testify against himself, only to provide physical evidence that will be used in a
comparison. If the suspect refuses to provide exhibits for comparison purposes, he may be held in
contempt until he complies. The Court might issue an order in this instance to authorize the use of
force to obtain the exhibits. In the United Kingdom, court orders are not available to collect
evidence by force. A jury is left to develop their own conclusions if the suspect refuses to submit to
dental evidence collection procedures. .
In the authors' experience, suspects are usually quite co-operative during the collection of physical exhibits.
However, this is not always the case and so the dentist who is requested to assist authorities to collect evidence
should see that provisions to ensure their personal security are in place.
Most commonly, the suspect is in custody and the dental examination takes place away from the practitioner's
dental office, perhaps in a jail or remand facility. Police will usually provide transportation to and from the site
and provide assistance to the dentist with respect to moving and setting up any equipment and supplies that are
needed for the examination.:
Full facial and profile photographs are produced. A reference scale to enable measurements to be taken from
the photographs should be included in the same plane as the teeth.
It is necessary to produce extremely accurate study casts of the teeth that record all of the physical traits and
characteristics of the dentition. All of the materials, including the trays, impressions and casts are maintained in
secure storage for eventual release to police authorities.
A sample of the suspect's bite is recorded using wax or a sample of silicone putty material designed for this
purpose. This exhibit should be photographed immediately after it is recorded. This will provide an opportunity
for future comparison of the photograph and the exhibit to verify that no distortion has occurred. The suspect
should be held in custody until the accuracy of all of the exhibits is determined to be satisfactory.
Forensic physical comparison of exhibits
The most common methods to determine if the suspect's teeth caused the bite mark include techniques to
compare the pattern of the teeth (shape, size, position of teeth, individually and collectively) with similar traits
and characteristics present in life-sized photographs of the injury using transparent overlays.
Some effort has been made to standardize the comparison procedures but, unfortunately, the conclusions are
often based on the expert's level of personal experience and judgement. The American Board of Forensic
Odontology has worked hard to establish guidelines for independent examination of the same evidence by
second and third odontologists before the primary expert submits a final report.
Regardless, many cases have been disputed because of differing expert opinions, attacks on the scientific basis
of physical comparisons because of the elasticity of skin and the question of uniqueness of the human dentition
In other words, don’t count on bite marks for conclusive evidence. Mrs. B.
Human bites as forensic biological evidence
During the process of biting saliva is deposited on the skin's surface. It has been shown that this trace evidence
is present in sufficient quantity and quality to enable typing of the DNA that is present in saliva from white blood
Conclusions from the analysis of bite mark evidence can assist the justice system to answer crucial questions
about interactions between people at the scene of a crime. Willingness by dentists to recognize, collect and
preserve this evidence can be invaluable in the resolution of heinous interpersonal crimes.