1. SFS2 Students will use various scientific techniques to analyze physical and trace evidence. c. Evaluate how post mortem changes are used to determine probable time of death SFS5 Students will evaluate the role of Forensics as it pertains to Medicolegal Death Investigation a. Identify the various causes of death b. Analyze evidence that pertains to the manner of death c. Interpret various modes of death. 1 Forensic Science II: Autopsy, Chapter 8 © 2012 Cengage Learning. All Rights Reserved

2. 2 Forensic Science II: Autopsy, Chapter 8 © 2012 Cengage Learning. All Rights Reserved o In 1998, Rutherford drove his car off the road. o The car caught fire and Rutherford died. o A $7 million life insurance policy would go to his wife, but only after an investigation. o An autopsy revealed: the skull fragments were in an unlikely position the bones indicated arthritis the dentures records didn’t match o Rutherford faked his death.

3. 3 Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

4. 4 Forensic Science II: Autopsy, Chapter 8 © 2012 Cengage Learning. All Rights Reserved o By law, deaths occurring under these circumstances must be investigated: Violent crime, suicide, or accident Within 24 hours of entering a hospital or having surgery A natural death when a doctor is not present or the patient is not under the care of a medical facility Occurs in police custody or in a correctional facility Results from a communicable disease that may pose a threat to public health.

5. 5 Forensic Science II: Autopsy, Chapter 8 © 2012 Cengage Learning. All Rights Reserved o Two systems of death investigation exist in the US The coroner system dates to 12C England; sometimes the position: is an elected official requires a medical doctor requires a forensic pathologist. The medical examiner system dates back to 1870 an experienced physician with advanced training in pathology

6. 6 The Manner of Death o The manner of death can be natural, accidental, suicidal, homicidal, or undetermined. o Sometimes it is difficult to determine the manner of death. o The most common manner of death is natural.

7. Forensic Science: Fundamentals & Investigations, Chapter 11 7 o Cause of Death Describes events leading to death Examples: stroke, drowning, shooting, etc. o Mechanism of Death Specific change in body that brought about death Examples: loss of blood, pulmonary arrest, etc.

8. 8 Lividity The Color of Death o When red blood cells break down, they turn a bluish-purple. o With decomposition, blood seeps down and settles in the lower parts of a body. o The discoloration that accompanies this becomes permanent after about 10 hours. o Warmth accelerates the process.

9. 9 The Rigidity of Death o At death, skeletal muscles cannot relax. o Without oxygen, calcium accumulates in these muscles. o The muscles become stiff. o This starts in the head and works its way down to the legs. o After about 12 hours, the muscle fibers begin to slowly dissolve, and softening begins.

10. 10 Many factors affect when rigor mortis sets in and how long it lasts: Ambient temperature The weight of the body The body’s clothing or lack of it Any illness the person had at the time of death The level of physical activity at the time of death Sun exposure

11. 11 Approximate times for rigor mortis in temperate regions (just a reference/estimate) Body temp. Body stiffness Time since death warm not stiff dead not more than 3 hrs warm stiff dead 3 to 8 hours cold stiff dead 8 to 36 hours cold not stiff dead more than 36 hours

12. 12 o In death, a body no longer generates warmth and begins to cool down. o To find the standard temperature of a corpse, a thermometer is inserted into the liver (sometimes it will be done rectally). o Body heat is lost at about 1 to 1.5 °F an hour. o Time of death determined by temperature calculations is expressed as a range of time.

13. Forensic Science: Fundamentals & Investigations, Chapter 11 13  Temperature of the surrounding environment  Type of clothing on the body  Wetness of the clothing  Air movement  Layers of clothing  Size of the individual

14. Forensic Science: Fundamentals & Investigations, Chapter 11 14

15. 15

16. 16 Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved o July 9, 1997 Champaign County, Ohio o Stepfather, Kevin Neal, claims stepchildren are missing from their back yard o Bodies discovered on September 6th were in the late stages of decomposition o Autopsies revealed Maggot infestation Absence of blowflies and screwworms Presence of cheese skipper fly in its 3rd instar stage o How were these insects evaluated?

17. 17

18. 18 o As the body decays, odors attract insects to the dead body. o The flies are the first to arrive. Blowflies and flesh flies are flesh feeders and will be the first in line. o If no trauma is present on the body, female blowflies will lay eggs in exposed body openings.

19.  Factors affecting insect development  Temperature  Wind  Time of day  Season  Exposure to elements  Estimation of time of death obtained by raising insects from scene in same conditions at lab.  Process is known as Accumulated Degree Hours (ADH) scienceinschool.org

20. 20 1. Blowfly eggs can be found in the moist, warm areas of a corpse within 8 hours after death. 2. They will have progressed to the 1 st of their 3 larva stages within 20 hours. 3. By the 4 th or 5 th day they will have progressed to the 3 rd of their 3 larva stages.

21. 21 4. By the 8 th or 12 th day the larvae will migrate away from the corpse to a dry place. 5. Becoming pupa and immobile within 18-24 days, they will change from white to dark brown. 6. By the 21 st -24 th day the pupa cases will split open and adult blowflies will emerge.

22. Fo re ns ic S ci en ce : Fu nd a m en tal s & In ve sti ga tio ns, C ha pt er 11 22 Image: http://www.nlm.nih.gov/visibleproofs

23. 23 Phormia regina Spiracles are incomplete Third-instar larvae

24. 24 Spiracles are complete Third-instar larvae

25. 25 Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved o Postmortem Interval- the time elapsed since a person died o When longer than 72 hours after death, entomology becomes important o Within 48 hours the female blowfly lays eggs in moist areas of the body

26. 26 o Forensic Entomology is used to determine time since death (the time between death and corpse discovery) o This is called postmortem interval or PMI. scienceinschool.org

27. 27 o Entomological evidence collection Identify the species Document larvae length Determine the instar Determine PMI documentingreality.com

28. 28 Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved  Observe and record all pertinent factors  Weather patterns (rainfall, wind, humidity, temperature, and exposure to light) during the PMI  Avoid disturbing insects within several feet of the body  Measure distance from body to insects  Collect samples of all insect stages on, near, and under the body

29. 29 Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved  Capture live flies with nets  Pin flies to a board, or  Preserve with 80% alcohol and 20% water Adult flies Eggs Largest larvae

30. 30 Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved o Ambient air 1 foot above the body 4 feet above the body o Ground Soil Surface 10 centimeters below 20 centimeters below o Center of a large infestation (if present)

31. Fo re ns ic S ci en ce : Fu nd a m en tal s & In ve sti ga tio ns, C ha pt er 11 31

32. 32  Time of injury vs. death  Estimation of time of death  Whether or not a corpse has been moved  Instances of insects as weapons  Child and elderly abuse and neglect  Single vehicle car accidents

33. 33 o “Roach Track” Confusion Roaches are notorious for confusing blood spatter analysis Blood trajectory is often critical to forensic investigations Roaches, silverfish and other household insects often travel through bloodstained areas

34. 34 o Shipments of illegal drugs often contain insect infestations, especially cannabis and heroine (derived from poppy plants.) o Analysis of insect “stowaways” can allow investigators to track country of origin, and in many cases the local area of cultivation. o PMI used to detect illegal drugs/poisons in fly larvae (consumed from corpses)