FORENSIC PATHOLOGY

1. FORENSIC PATHOLOGY Izabela Dembowska-CZUBATY Introduction to ForensicSciences

2. DEATH CAUSE OF DEATH • NATURAL – no disease, no injury, recently quite uncommon • DISEASE – out of the interest of forensic medicine and prosecution • INJURY – remains in the scope of interest of prosecution (homicidal, accidental and suicidal) TIME OF DEATH • SUDDEN – no agony, usually injuries • SLOW – with agony, usually diseases, rarely injuries

3. DEATH MANNER OF DEATH • ACCIDENTAL • SUICIDAL • HOMICIDAL • NATURAL

4. DEATH STAGES OF DEATH • FALSE DEATH (vita minima) – a person is still alive but living functions remain on a very low level • CLINICAL DEATH – a person can be still brought to life (no heart beat, no breathing) • BRAIN DEATH – allows for the announcement that the person died • INTERLETHAL STAGE – brain is damaged but some functions of body can be observed (growth of hair and nails) • BIOLOGICAL DEATH – inevitable damage to cells

5. DEATH CONDITIONS OF DEATH • RIGOR MORTIS • LIVOR MORTIS • ALGOR MORTIS • PALLOR MORTIS – discoloration (white) of skin

6. DEATH RIGOR MORTIS The muscles of the body initially become flaccid after death. Within 1–3 hours following death, the muscles begin to become noticeably increasingly rigid and the joints immobile (freeze) due to a process known as rigor mortis (postmortem rigidity, rigor). When a body stiffens, it remains in that position until rigor passes or it is physically overcome (broken), such as when a joint is forcibly moved. Since the chemical process of rigor is irreversible, fully developed rigor will not recur in an area in which it has been broken or in an area in which it has already passed.

7. DEATH LIVOR MORTIS Livor mortis (postmortem hypostasis, lividity) is the discoloration of the body after death due to the gravitational settling of blood which is no longer being pumped through the body by the heart. Livor mortis is usually noticeable approximately 1 hour after death and is often apparent earlier, within 20–30 minutes. The discoloration increases in intensity and usually becomes “fixed” in about 8–10 hours. The formation of livor may be hindered or prevented by pressure applied to the body’s surface because the small blood vessels become compressed and blood is prevented from settling into them.

8. DEATH ALGOR MORTIS (body cooling) After death, the body equilibrates with the surrounding environmental temperature. Although this usually involves algor mortis (cooling of the body), in some cases, such as a body laying on a sidewalk in direct sunlight, the body may absorb heat. However, in most cases, the body will progressively lose temperature until it equilibrates with its environment. Many studies have examined this progressive decrease in body temperature to attempt to develop formulae which could be used to calculate the postmortem interval.

9. DEATH DRYING • drying • autolysis – damage of the cell structures • rotting (green discoloration) • adipocere • mummification • decomposition in peat bogs

10. ROTTING The environment is a major determinant of the type of decomposition the body undergoes and the rate at which it proceeds. Bodies that are buried in earth, submerged in water, left in the hot sun or placed in a cool basement will not look the same after the same postmortem interval. In general, as rigor passes, green discoloration of the skin becomes evident. The green discoloration typically begins on the abdomen and then spreads to the rest of the body. At room temperature, the right lower abdomen turns green at about 24 hours after death and the entire abdomen is green by 36 hours. As with other postmortem changes, the onset and progression of the green discoloration is quite variable.

11. ADIPOCERE Adipocere is a term derived from Latin which literally means “fat” (adipo) “wax” (cera). It refers to a hard gray-white waxy substance formed during decomposition. It is an uncommon change, occurring particularly in bodies buried for an extended period of time in cool, moist environments and is most commonly seen after bodies have been submerged in water during the winter months. Not all bodies having adipocere are found in water. For example, bodies found in plastic bags which provide a moist environment may also undergo this change.

12. MUMMIFICATION Mummification occurs in hot dry environments where the body is able to dehydrate and bacterial proliferation is minimal. The skin becomes dark, dry and leathery. The internal organs desiccate and shrink. Most mummification occurs in the summer months but may also occur during the winter if the temperature is warm enough. An entire body can mummify in a few days to weeks. As the skin dries and hardens, the soft tissues decompose. After a few weeks, an entire body may appear preserved with some shrinkage due to dehydration.

13. DEATH DETERMINATION OF DEATH • conditions of death • interlethal signs • gastric contents • bleeding level

14. EXAMINATION OF BODY EXTERNAL EXAMINATION OF BODY – at the crime scene INTERNAL EXAMINATION OF BODY – autopsy

15. EXTERNAL BODY EXAMINATION • order of events • people involved in examination • a scope of activities that may be conducted • preservation of evidence at the crime scene

16. INTERNAL BODY EXAMINATION TYPES OF AUTOPSY (legal reasons) • scientific • forensic TYPES OF AUTOPSY (time) • before body is burried • after exhumation TYPES OF AUTOPSY (purpose) • determination of the cause and manner of death • grafting of internal organs

17. INTERNAL BODY EXAMINATION AUTOPSY PURPOSES • determination of the cause and manner of death • determination of the time of death • determination of injuries • determination of tools that may have caused injuries • determination of the circumstances of death

18. THANK YOU Materials prepared basing on: Jay Dix, Michael Graham, Time of Death, Decomposition and Identification. An Atlas, CRC Press 2000.