1. Forensic Pathology
and Odontology

2. What is Forensic Pathology?
Definition:
- investigation of sudden, unnatural, unexplained or violent deaths
- notice: not all deaths warrant autopsy
Ex. Old age, terminal illness
- but violent, suspicious deaths in healthy individuals and some accidental deaths warrant the use of an autopsy (post-mortem examination of a body to determine cause of death)

3. Modern Goals of Autopsies
Determine the identity of the decedent
Determine the cause of death
Determine the manner of death
Determine the mechanism of death
Determine time of death

4. Cause and Manner of Death
Cause of Death
Manner of Death
the injury or disease that initiated death
Ex. cancer
explains how the cause arose; such as natural, accident, homicide, suicide (sometimes undetermined)
Ex. Struck by lightening (accident)

5. The Medical Examiner Requires a Doctor of Medicine Degree
Responsibilities include autopsy, histology, and forensic photography
Perform around 250 autopsies a year
Review around 1,400 filed medical examiner cases a year
Provide instruction in Forensic Pathology
Salary: $97,000 - $170,000 a year*
*Source: The Forensic Casebook pg

6. Examination Protocol Most ME’s visit the scene
Dental/medical history can be provided if identity of victim is known
Any use of resuscitation, injections, IV or thoracic lines, intubations, or bare-handed handling by medical personnel is vital knowledge

7. Examination Protocol Visual inspection Injury inspection
Internal examination
Presentation to other experts
Reconciliation of all exhibits
Presentation of findings

8. Three Types of Decomposition
Rigor mortis:
medical condition that occurs after death and results in the shortening of muscle tissue and the stiffening of body parts in the position they are when death occurs
Immediately following death, muscles relax and then become rigid
Occurs in the first 24 hours and disappears within 36 hours

9. Three Types of Decomposition
Livor mortis:
Medical condition that occurs after death and results in the settling of blood in areas of the body closest to the ground
Skin appears as a dark blue or purple in the areas where the blood has settled due to gravity
Begins immediately following death and lasts up to 12 hours after death

10. Three Types of Decomposition
Algor mortis:
Postmortem changes that cause a body to lose heat until it reaches room temperature
Good for determining time of death
Average heat loss: 1 degree F per hour
Affected by clothing, weather conditions, fat content

11. Visual Inspection
Before the visual inspection begins, blood is drawn, X-rays taken, and inspected for sharps
Visual examination can begin with a nude or clothed body
Entire body is photographed

12. Visual Inspection cont…
Clothing is examined for rips, tears, or trace evidence
Clothing is removed, dried, & packaged; descriptions of clothing (including size/brand) recorded for autopsy report
Blood-stained clothing sent out for examination; blood stains on body swabbed for identification
Head combed for trace, foreign hairs, & other evidence

13. Visual Inspection cont…
Rape kit may be included at this stage if warranted
Body openings (ears, vagina, etc.) examined for foreign objects/trace evidence
Hands (bagged at the scene) are examined; fingernail scrapings
Fingerprint/footprint cards taken
Entomological samples taken if needed
Notations of visual injuries are made & photographed; tattoos/body markings noted
General health noted along with hair & eye color

14. Visual Inspection cont…
UV photography used to reveal old bruises or new ones not yet surfaced
Lasers/oblique lighting turn up trace such as hair, pollen, blood, saliva, semen, even fingerprints
Birthmarks, tattoos, & distinguishing scars used as recognizable marks for identification

15. Injury Inspection Penetrating wounds Non-penetrating wounds
caused by bullets, knives, bombs, etc.
- full extent of these wounds requires more than visual examination
- caused by blunt force trauma, hand/finger impressions, burns, needle marks

16. Injury Inspection cont…
Penetrating wounds such as those caused by bullets draw special attention
- presence of gunpowder around wound
- long range bullet wounds result in a hole with no other surface information
- shots held to the skin give a hole & “rim burn”
- short range shot may singe body hair and leave similar marks as a skin-held shot but no burn mark
- inches to feet away shots leave “stippling” marks

17. Injury Inspection cont…
Bullet wound can change shape because skin is elastic so gun caliber cannot always be estimated
Gunshot entry wounds are usually smaller than exit wounds
Bullets that hit bone often leave a star pattern on bone surface
Knife wounds are three dimensional; recognizable by experienced examiners without casting; most are by kitchen ware

18. Injury Inspection cont…
Non-penetrating wounds
- blunt-force trauma leaves marks
- hand & finger impressions on skin are measured for finger span and size
- bite marks can be photographed and cast made
- burns; frost bite; rope marks from hangings appear with an upward angle (fake ones have a horiz. line)
- needle marks indicate drug use

19. Internal Inspection (Autopsy)
Most dissections begin with a “Y” incision over the torso
One cut - arc across chest from shoulder to shoulder
Second cut - long cut that extends from base of the breast bone to the pubic bone (curves around navel)

20. Internal Inspection (Autopsy) cont…
Organs are removed from the top down; each is massed out on a scale
Rib cutters and spreaders open the chest
Lungs are examined for damage and heart tissue will be sampled

21. Internal Inspection (Autopsy) cont…
Throat, esophagus, trachea, and upper spine examined; broken hyoid bone indicates strangulation
Stomach contents are examined and help determine time of death; tie victim to a specific place & time; intestines examined as well
Liver, spleen, & pancreas are sectioned for histology & drug presence

22. Internal Inspection (Autopsy) cont…
Bladder sample taken (urine) for testing of drugs
Presence of blood in urine can mean blunt force trauma over the kidneys
Women are examined for pregnancy, sexual interference, & semen
Once the internal examination is complete, the organs are replaced inside the body & the body is sewn up

23. Internal Inspection (Autopsy) cont…
Head is examined last; eyes are first
Hemorrhages to the eyes or lids (petechiae) indicate lack of circulation to the head (strangulation)
Single incision made - arch from one ear, over forehead, to other ear; face is flipped forward
Face area is examined for bruising beneath the skin
Skull is opened with a saw; brain examined and weighed

24. Other Autopsy Facts Exhumations
- body that has been buried is dug up for examination
Partial bodies/Amputations
- ME sometimes must “reconstruct” a victim from their body parts
- body parts can sometimes help police reconstruct the crime or profile the killer

25. Presentation to Other Experts
Medical examiners are NOT expected to see EVERY trauma ever inflicted on a victim
ME must rely on histology, toxicology, and other fields to help with cause of death
ex. Scuba deaths, animal bites, pharmacy

26. Reconciliation of All Exhibits
Prior to the completion of the autopsy, all samples, reports, and exhibits are accounted for and checked for accuracy
All evidence (ex. bullets) is returned

27. Presentation of Findings
Final presentation is the autopsy report
Describes all findings, steps taken, and opinion of the examiner on the cause, method, and manner of death

28. Forensic Odontology
Definition: the application of dental science to help identify individuals and the study of teeth in bite mark analysis
Job title: Forensic odontologist

29. Identifying Remains
Victims can be identified by using a complete jaw, fragment of a jaw, or even just a few teeth
Dental x-rays best source for identification
Show relative positions of teeth, fillings, and other materials contained in the tooth
Forensic odontologist may also assist in the autopsy (take notes on teeth and cranial features)
Police use these dental findings, enter them into a computer and look for a close comparison

30. Example of Dental filling

31. Identifying Unknown Remains cont.
Often called to mass disaster sites (such as airplane crashes, fires, bombings, terrorist attacks, etc.)
May be called to mass graves after political crimes of massacres have been committed (ex. Rwanda and Guatemala)
Genocide victims of Rwanda and native indigenous people of Guatemala were killed by government

32. Analyzing Bite marks
Criminals (and victims) sometimes leave bite marks
Can link a suspect to a victim and vice versa
Dental impressions often left in food too (chewing gum; also a good DNA sample)

33. Computer Imaging with Dental Records
Computer imaging technology can generate an outline of teeth
It is laid over top a digital photograph of the human bite mark on the victim
Called “compound overlay”

34. Computer Imaging continued
Image can be zoomed in for a close up
Look at edges of suspect’s teeth and compared with the injury pattern
In court, forensic odontologist would then testify to the strong association between the victim’s injury marks and the dental impressions of the suspect

35. How to Become a Forensic Odontologist?
First become a dentist
Need bachelor of science degree
Go to dental school (Doctor of Dental Science)
Gain experience in the field of dentistry
Take courses on forensic odontology supported by the American Board of Forensic Odontology