Shoot Around Explain the difference between rigor mortis, algor mortis, and livor mortis. If a person’s body temperature is typically 37 degrees Celsius and the person will typically about 1.5 degrees per hour after death, then how long was a person dead if their body was 28 degrees when it was found?

Methods to Determining Death Review Objective: Students will describe how and why the dead body of a victim contains an abundance of evidence that can be used to identify the mechanism of death Essential Question: How can we use the body temperature, body stiffness, and body color to determine the time of death?

Manner of Death Four ways people die Natural Accidental Suicidal Interruption and failure of bodily function resulting from age or disease Accidental Unplanned event Suicidal A person purposely kills oneself Homicidal Death of one person caused by another

Example A man was shot in the head, which led to exsanguination and brain death. What is the manner of death? Homicide due to the gun shot.

Your Turn! A woman smoked since she was 19 and died at the age of 65 of lung cancer, which caused her to go into respiratory failure. What is the manner of death?

Algor Mortis Uses body temperature to determine time of death Normal body temperature is 370C (98.60F) A body loses heat at a rate of 1.40C per hour until the ambient temperature is reached Rate varies according to environmental temperature Once ambient temperature is reached, you cannot use this method to determine time of death

Question: What are some Factors that would affect Algor Mortis? Ambient temperature Wind? Excess body fat? Clothing

Question: What are some Factors that would affect Algor Mortis? Ambient temperature Wind? Excess body fat? Clothing

Think-Pair-Share Why is algor mortis a difficult method to use when determining time of death? First, take two silent minutes to think of answer Second, take two minutes and talk with an elbow partner about your thoughts Third, three groups share your thoughts to the class

Rigor mortis: The medical condition that occurs after death Results in the shortening of muscle tissue and the stiffening of body parts Body stays in the position they are in when death occurs Begins within 12 hours and ends after 48 hours After 48 hours, muscle cells begin to autolyse 10 10

Rigor Mortis Time Event Appearance 2-6 hours Rigor begins eyelids, Jaws stiffen After 2 hours then center of body stiffens 12 hours Complete Rigor Entire body rigid 15-36 Slow loss of rigor, small muscles first Lost in head and neck, last is bigger leg muscles 36-48 Rigor disappears, muscles become relaxed

Livor mortis * Is a settling of the blood in the lower portion of the body ** Causing a purplish red discoloration of the skin. *** Discoloration does not occur in the areas of the body that are in contact with the ground or another object,

3. Livor mortis

Autopsy and time of death cont… Livor mortis: the medical condition that occurs after death and results in the settling of blood in areas of the body closest to the ground Evident 30-120 minutes postmortem 8-12 hours (24-36 hours in cooler temps) postmortem- maximum color or “fixed” livor mortis due to hemolysis (blood vessels break down) May occur antemortem (before death) in slow deaths Can congest internal organs 15 15

Potassium levels in vitreous humor + Clouding of the cornea Cornea is the clear covering of your eyes Becomes cloudy and opaque after death Takes only a few hours after death if eyes are open at death It takes 24 hours if eyes are closed at death. Cornea

Potassium levels in vitreous humor + Clouding of the cornea Vitreous humor is the jelly like fluid found in the eye. Concentration of potassium increases slowly during first few days Vitreous humor

5. Stomach Contents

Stages of Decomposition Initial decay Corpse appears normal, internal bacterial decay and autolysis begins Putrefaction Odor of decaying corpse swollen Black Putrefaction Very strong odor, flesh appears black, gases escape, corpse collapses Dry Decay Corpse is almost dry, further decay slows from lack of moisture

Stages of Decomposition 2 days Cells autolysis Greenish purple staining occurs, blood decomposing Skin takes on Marbled Appearance 4 days Skin blisters Abdomen swells with carbon dioxide Due to bacteria in intestines 6-10 days Corpse bloats with CO2 Corpse eventually bursts Fluid begins leaking from openings as cell membranes rupture Eyeballs liquefy Skin sloughs off