Chapter 11 Death l use insect evidence to

Chapter 11 Death ✓ l use insect evidence to estimate time of death l explain how environmental factors can affect the ✓ l l 1 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

TODAY’S GOALS (2 of em’): 1. 2. Identify the definition of death Demonstrate knowledge of: – cause of death – manner of death – mechanism of death 2

THE BIG IDEA l DEATH = the point where resuscitation (bringing back to life ) becomes impossible * * * It helps to think of death as a process not an instant event * * 3 *

Imagine you’re a forensic pathologist l Your job is to identify the following 3 things: * Depending 1. Cause of death on your 2. Manner of death answers a 3. Mechanism of death formal 4 investigation

♫ ♪ In the tune of “Frosty the Snowman” 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 5

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

CHECKING FOR UNDERSTANDING l l Cause of death SHOT Gang member shot in a retaliation killing = _____ Failing shop owner with family and life insurance policy CAR ACCIDENT 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 = _______ SUFFOCATION Man survives atomic blast. 10 years later he gets CANCER cancer and dies = _____ 7

♫ ♪ In the tune of “Frosty the Snowman” 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 8

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

5 Manners of Death 1. Natural – failure of body functions - old age - disease 2. Accidental – unintentional actions - Falling from a ladder - Car accident 3. Suicide – purposefully killing oneself - overdose - Hanging 4. Homicide – intentional actions of other(s) 5. Undetermined – when a manner of death can’t be determined 10

CHECKING FOR UNDERSTANDING l l l Manner of death 80 yr old dies peacefully in her sleep = _____ NATURAL HOMICIDE Gang member dies in a retaliation killing = _____ Failing shop owner with family and life insurance SUICIDE 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 = _______ ACCIDENTAL Can’t be determined = ________ UNDETERMINED 11

♫ ♪ In the tune of “Frosty the Snowman” 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 12

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

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

Cause, Manner, & Mechanism Assignment (5 minutes or less) On a new sheet of paper (that will be collected) write your name, date, and period. 2. Neatly create a sentence or two explaining a man’s death. (Using professional language) 3. Switch papers with a neighbor and then print your name at the bottom of their paper. 4. Identify the cause, manner, mechanism of their death story 5. Write a few sentences defending why you answered 15 the way you did (use the word “because”) 1.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

T UL AD 2 ND PA ins tar bre ak 48 rts sta 1 SE BO T IN DY e ibl be vis 0 to Entomology (BUGS) PU 24 3 RD 1 st ins tar Finishing your cheat sheet timeline 2 10 Livermortis (BLOOD) 6 hrs days 10 hrs Rigormortis (STIFFNESS) days 10 Algormortis (TEMP) hrs days

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: 1. Food is still present in the stomach. 2. The stomach is empty but food is found in the small intestine. 3. The small intestine is empty but waste is present in the large intestine. 31 Forensic Science: Fundamentals & Investigations, Chapter 11

Time of Death—Stages of Decomposition Choose: A. Within 2 days. B. After 4 days. C. Within 6 -10 days. 1. 2. 3. 4. 5. 6. 7. 8. 9. 32 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

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

Time of Death—Insects 1. Blowfly eggs can be found in the moist, 34 warm areas of a corpse within 8 hours after death. 2. They will have progressed to the 1 st of their 3 larva stages (illustration of one shown above) 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. Forensic Science: Fundamentals & Investigations, Chapter 11

Time of Death—Insects 4. By the 8 th or 12 th day the larvae will migrate 35 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 (illustration of one shown above) will emerge. Forensic Science: Fundamentals & Investigations, Chapter 11

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

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