1. Chapter 11 Death ✓ ✓ use insect evidence to estimate time of death
explain how environmental factors can affect the estimated time of death
Properly i.d. cause, manner & mechanism of death
explain the development of livor, rigor, and algor mortis following death
use evidence of these to estimate time of death
use evidence on stomach contents to estimate time of death ✓

2. TODAY’S GOALS (2 of em’):
Identify the definition of death
Demonstrate knowledge of:
cause of death
manner of death
mechanism of death

3. THE BIG IDEA
DEATH = the point where resuscitation (bringing back to life ) becomes impossible
Students make 2 columns on board (alive vs dead) “Q: How do you know someone is alive or dead?”
* * * It helps to think of death as a process not an instant event * * *

4. Imagine you’re a forensic pathologist
Your job is to identify the following 3 things:
Cause of death
Manner of death
Mechanism of death
* Depending on your answers a formal investigation may be opened *

5. ♫ ♬ ♪ ♪ ♪ In the tune of “Frosty the Snowman” Cau-ses are e-vents
by Walter “Jack” Rollins and Steve Nelson
Cau-ses are e-vents
The man-ners are short and sweet
Mech-an-ism is a body change
Lead-ing you to die ♪ ♪ ♪ ♬

6. C.O.D. = the event that led to someone’s death
Cause of death
C.O.D. = the event that led to someone’s death
Shark attack
Cancer
Shot

7. CHECKING FOR UNDERSTANDING
Cause
of death
CHECKING FOR UNDERSTANDING
Gang member shot in a retaliation killing = _________
Failing shop owner with family and life insurance policy drives off a cliff = ______________
Hospital receives a gun shot victim who survived a mob hit. Days after he is stabilized the mob returns and suffocates him with a pillow = _____________
Man survives atomic blast. 10 years later he gets cancer and dies = __________
SHOT
CAR ACCIDENT
SUFFOCATION
CANCER

8. ♫ ♬ ♪ ♪ ♪ In the tune of “Frosty the Snowman” Cau-ses are e-vents
by Walter “Jack” Rollins and Steve Nelson
Cau-ses are e-vents
The man-ners are short and sweet
Mech-an-ism is a body change
Lead-ing you to die ♪ ♪ ♪ ♬

9. Manner of death
Manner of death = the short official way a person’s death is described

10. 5 Manners of Death Natural – failure of body functions
old age
disease
Accidental – unintentional actions
Falling from a ladder
Car accident
Suicide – purposefully killing oneself
- overdose
- Hanging
Homicide – intentional actions of other(s)
Undetermined – when a manner of death can’t be determined

11. CHECKING FOR UNDERSTANDING
Manner
of death
CHECKING FOR UNDERSTANDING
80 yr old dies peacefully in her sleep = _________
Gang member dies in a retaliation killing = _________
Failing shop owner with family and life insurance policy drives off a cliff = __________
30 years after leaving his family on Christmas eve a man’s mummified body is found in the chimney wearing Santa suit = _____________
Can’t be determined = _______________
NATURAL
HOMICIDE
SUICIDE
ACCIDENTAL
UNDETERMINED

12. ♫ ♬ ♪ ♪ ♪ In the tune of “Frosty the Snowman” Cau-ses are e-vents
by Walter “Jack” Rollins and Steve Nelson
Cau-ses are e-vents
The man-ners are short and sweet
Mech-an-ism is a body change
Lead-ing you to die ♪ ♪ ♪ ♬

13. Mechanism of Death = the physiological change that led to death
Massive blood loss
Multiple organ failure
Trauma to the brain

14. CHECKING FOR UNDERSTANDING
Mechanism
of death
CHECKING FOR UNDERSTANDING
80 yr old dies in her sleep = __________________
Gang member shot = _________________________
Shop owner with life insurance policy drives his car off a cliff = ________________________________
30 years after leaving his family on Christmas eve a man’s mummified body is found in the chimney wearing Santa suit = __________________________
Can’t be determined = _______________
multiple organ failure
bleed to death (exsanguination)
Trauma to the brain (cerebral contusion)
Stoppage of breathing (asphixia)
UNDETERMINED

15. Cause, Manner, & Mechanism Assignment (5 minutes or less)
On a new sheet of paper (that will be collected) write your name, date, and period.
Neatly create a sentence or two explaining a man’s death. (Using professional language)
Switch papers with a neighbor and then print your name at the bottom of their paper.
Identify the cause, manner, mechanism of their death story
Write a few sentences defending why you answered the way you did (use the word “because”)

16. THE BODY IS A CRIME SCENE
Forensic Science: Fundamentals & Investigations, Chapter 11

17. 4 WAYS TO UNDERSTAND A BODY AS CRIME SCENE
Livor mortis –
blood settling
Rigor mortis –
muscles stiffening and relaxing
Algor mortis –
Temperature loss
Entimology –
insect life stage

18. Livor Mortis L.M. becomes permanent after 8 hours.
Livor – bluish color (Latin)
When red blood cells break down, they turn a bluish-purple.
With no circulation, gravity pulls blood down and settles it in the lower parts of a body.
Warmth accelerates the process.
L.M. START TO BE VISIBLE 30 MINUTES TO 120 MINUTES AFTER DEATH
L.M. becomes permanent after 8 hours.

19. Livor mortis
Forensic Science: Fundamentals & Investigations, Chapter 11

20. Livor mortis
Forensic Science: Fundamentals & Investigations, Chapter 11

21. IGNORE THE PILLOWS
This body was found with livor mortis on the top side of the body. What must have happened to allow this?

22. Rigor Mortis
RIGOR MORTIS = muscle stiffening and relaxing after death
Without oxygen, calcium accumulates in muscles.
As a result, the muscles become stiff.
This starts in the small muscles (head and appendages) and works its way to large muscles (legs).

23. Rigor Mortis
2 hours A.D. = rigor begins at small muscles and moves to larger muscles
12 hours A.D. = body is most rigid
15 hours A.D. = rigor begins to relax small muscles > larger
36 hours A.D. = stiffness will have disappeared
If a body has no visible signs of rigor, it has been dead less than 2 hours or more than 36.
The state of decay will tell you which is which

24. RIGOR MORTIS
Forensic Science: Fundamentals & Investigations, Chapter 11

25. AL GORE – TEMP CHANGE
Forensic Science: Fundamentals & Investigations, Chapter 11

26. Algor Mortis Algor Mortis = coldness of death
In death, a body no longer generates warmth and begins to cool down.
Thermometer is inserted into the liver

27. Temp (degrees F) Time (hours) DEATH (98º F) AMBIENT TEMPERATURE
Forensic Science: Fundamentals & Investigations, Chapter 11

28. Some factors that affect algor mortis
Weight / insulation of individual
Clothing layers
Humidity / wetness
Forensic Science: Fundamentals & Investigations, Chapter 11

29. Entomology (blow fly) Egg = 2 mm 1st instar = 5mm 2nd instar = 10mm
Head
Egg = 2 mm
1st instar = 5mm
2nd instar = 10mm
3rd instar = 17mm
Pupa = 9mm (skin actually shrinks & hardens)
Adult (crawling) = varies*(Blow flies do not fly much for a day or two while their body is hardening)
Adult (flying) = useless for FS
Breathing holes

30. Finishing your cheat sheet timeline
3RD instar
1st instar
2ND instar
PUPA
ADULT 24 48
hrs
break
Entomology
(BUGS)
days 1 2 6
starts to be visible
SET IN BODY 10
hrs
Livermortis
(BLOOD)
days 10
hrs
Rigormortis
(STIFFNESS)
days 10
hrs
Algormortis
(TEMP)
days

31. Time of Death—Stomach and Intestinal Contents
Based on these specifics, give an estimate for each of these on how much time has passed since the meal was eaten:
Food is still present in the stomach.
The stomach is empty but food is found in the small intestine.
The small intestine is empty but waste is present in the large intestine.
Forensic Science: Fundamentals & Investigations, Chapter 11

32. Time of Death—Stages of Decomposition
Choose: A. Within 2 days. B. After 4 days. C. Within 6-10 days.
Fluids begin to leak from body openings as cell membranes rupture.
Discoloration of the face.
The skin sloughs off.
The skin blisters.
Green and purplish staining from blood decomposition.
The corpse bloats.
Eyeballs and other tissues liquefy.
The abdomen swells.
Marbling appearance on the skin.
Forensic Science: Fundamentals & Investigations, Chapter 11

33. Time of Death—Insects
Besides recording data about the environment at a crime scene, a forensic entomologist collects insect evidence.
Within minutes of a death, certain insects arrive to lay their eggs on the warm body. Blowflies are a common example.
As a corpse progresses through the stages of decomposition, other kinds of insects arrive.
Forensic Science: Fundamentals & Investigations, Chapter 11

34. Time of Death—Insects
Blowfly eggs can be found in the moist, warm areas of a corpse within 8 hours after death.
They will have progressed to the 1st of their 3 larva stages (illustration of one shown above) within 20 hours.
By the 4th or 5th day they will have progressed to the 3rd of their 3 larva stages.
Forensic Science: Fundamentals & Investigations, Chapter 11

35. Time of Death—Insects
By the 8th or 12th day the larvae will migrate away from the corpse to a dry place.
Becoming pupa and immobile within days, they will change from white to dark brown.
By the 21st-24th day the pupa cases will split open and adult blowflies (illustration of one shown above) will emerge.
Forensic Science: Fundamentals & Investigations, Chapter 11

36. Time of Death—Insects
Because scientists know how long it takes for the various stages of development at given temperatures, forensics entomologists can determine when the insects arrived.
Because life cycles are affected by fluctuations in the daily environmental conditions, insect evidence cannot provide an exact time of death.
Insect evidence, nonetheless, can yield a close estimate.
Forensic Science: Fundamentals & Investigations, Chapter 11

37. Summary
A body decomposes through the 3 changes of livor, rigor, and algor mortis.
Forensic scientists use evidence from these to estimate the time of death.
They also use stomach contents and insect evidence to estimate the time of death.
It is also important to remember how environmental factors can affect the estimated time of death.
Forensic Science: Fundamentals & Investigations, Chapter 11