Bellringer

1. Bellringer • What do you think entomology is?

2. Objective • Learn what entomology is and what the three types of entomology are.

3. Reminder • The detailed sketch of you serial killer poster is due this Friday.

4. Forensic Entomology

5. Entomology • What is entomology? • Entomology is the scientific study of insects!!! • EWWWW GROSS!!!!

6. Background check • People come from all different backgrounds, so let’s see who knows what about insects. • On page 370 of the textbook take the quiz and test your knowledge of the insect world. (1-14) • Record your answers in your notes and in complete sentences so you can refer back later.

7. Taxonomy • Taxonomy is the classification of things in an orderly way that indicates natural relationships. • This is how we sort different living creatures.

8. Steps of Taxonomy • Largest (most general) category is Kingdom. The smallest (most specific) category is Species.

9. Example

10. What does this have to do with forensics? • Forensic Entomology is the use of insects and other arthropods to aid in legal investigations. • Arthropods are animals characterized by jointed legs, a segmented body, and a hard, nonliving exoskeleton.

11. The 3 general areas of forensic entomology • Urban entomology • Insect damage to structures • Stored products entomology • Insects infesting foodstuffs • Medicolegal entomology • Insects that inhabit human remains

12. Forensic Entomology • Forensic scientists are mostly concerned with medicolegal entomology. • They commonly use it to the determine postmortem interval associated with the time of death. • Postmortem Interval is the time elapsed since a person has died.

13. Check point • What is forensic entomology? • What are the three types of entomology?

14. Bellringer • What is Entomology? • Remember your detailed sketch is due tomorrow.

15. Objective • Learn about the process of death, this way we can better understand the use of insects in, on, or around a dead body.

16. First • Before we can study how insects take over a person’s body once they are dead we must learn and understand the processes that happen after a person dies.

17. The process of Death • First off, death is a process and not an event. • Cause of death is not the process of death. • Different tissues and organisms in a living body die at different rates.

18. Determining the time of death • Most accurate if the body is found within the first 24 hours. • Use the three indicators • Algor mortis • Livor mortis • Rigor mortis • After these time periods have passed other methods must be used instead. • Estimations based on the environment and the scene.

19. Algor mortis • Algor mortis refers to the cooling rate of the body after death. • Immediately upon death, the body can no longer metabolically maintain its temperature of 98.6 degrees Fahrenheit and begins to equalize its temperature to that of its environment. • Measuring the internal body temperature can give you some indication of the time of death.

20. Newton’s Law of cooling • Newton was one of the best physicist ever. • Wrote an equation to predict the rate of change in the temperature of a body using the starting body temp and the air temp.

21. Glaister Equation • Newton’s method doesn’t work well for dead bodies. • The Glaister Equation is used from 1 to 36 hours after death, but is most accurate within the first 12 hours.

22. Glaister Equation • Generally a body cools about 1 to 1.5 degrees Fahrenheit per hour until it reaches ambient temperature. • The temperature of the environment, type of clothing on the body, wetness of the clothing, air movement, # of layers of clothing, and other conditions must be taken into consideration. • Also, the greater the ratio of surface area to mass, as with children or smaller adults, the faster the body cools.

23. Livor mortis • Livor mortis refers to the pooling of blood in the body due to gravity after the heart stops. • It appears on the skin as a purplish-red discoloration (like a bruise) and can give an indication of the position of the body at the time of death.

24. Liver mortis • It begins within a half hour after death and is most evident within the first 12 hours • After 12 hours the discoloration will not move regardless of how the body is repositioned • This fact is useful when determining whether a body has been moved after death

25. Rigor mortis • Rigor mortis is a stiffness in the muscles that occurs shortly after death. • Immediately upon death muscles begin to relax, but then some enzymes in your muscles begin to act and cause your muscles to become more rigid.

26. Rigor mortis • Rigor mortis begins in the smaller muscles so it’s first observed in the face, neck and jaw. • The noticeable stiffness of rigor mortis can occur within a few hours after death and is gone within approximately 30 hours, leaving the body limp.

27. Rigor mortis • Rigor mortis begins to disappear in the same order in which it began. • Rigor mortis is affected by the environmental conditions such as temperature, dehydration, condition of muscles, and their use prior to death • There are uncertainties in determining the time of death from rigor mortis

28. Estimating Time of Death

29. Checkpoint • What are algor mortis, livor mortis, and rigor mortis?

30. Reading Activity • Read pages 380 and 381 and then answer the following questions • What is autolysis and when is it first observed? • What is putrefaction and why is it so smelly? • What is mummification and why doesn’t it happen to every dead body? • What is digenesis? • What variables have the largest effect on the rate of decomposition? • How long would it take a body to become a skeleton if it was out in 45 degree Celsius weather?

31. Case Study • Is it possible to stop a body from decomposing at all? • Read the case study on pages 381 to 381. “Colonel William Shy” • How was this possible?

32. Tomorrow • Life cycle of Insects and the Insects of Death

33. Bellringer • What is algor mortis and how is it different from livor mortis?

34. Objective • Learn how the life cycle of insects is used by forensic scientists to determine the time of death of a dead body.

35. Sketches • Please pass up your sketch of your final poster.

36. Reading Activity • Read pages 380 and 381 and then answer the following questions • What is autolysis and when is it first observed? • What is putrefaction and why is it so smelly? • What is mummification and why doesn’t it happen to every dead body? • What is diagenesis? • What variables have the largest effect on the rate of decomposition? • How long would it take a body to become a skeleton if it was out in 45 degree Celsius weather?

37. Decomposing Whale • Remember the process of death is not one step. • As a formerly living thing decomposes gasses are released inside the body which can create very large amounts of pressure. • Warning this video is disgusting…like really really gross… • https://www.youtube.com/watch?v=d2CfYOJ5oxk

38. Case Study • Is it possible to stop a body from decomposing at all? • Read the case study on pages 381 to 381. “Colonel William Shy” • How was this possible?

39. Bellringer • What is livor mortis and how does it help forensic scientists determine the time of death of a body?

40. Objective • Understand how insects are used to calculate the time of death of a body.

41. Serial Killer Projects • The class has an average of 29.5/40 right now…or a 74% • Remember these were the “easiest” parts. • The papers, presentations, and posters will be graded much more critically.

42. Life Cycle of Insects • Knowing the life cycle of insects can help forensic scientists determine how long they have been infesting a body. • Egg – 12 hours • Larva (maggot) – 4 days • Pupa (Dark hard shell) – 3 days • Winged Adult (Flies) – 12-24 hours

43. Life Cycle of Insects • Two bodies are found in the same area. Which body has been dead longer? • One that is found with flies on it but no signs of anything else. • One that is found with flies on it and with empty pupae.

44. Insects of Death Reading • Read pages 384 to 385, and then answer these questions. • What are the two most common insects found on corpses? • How many species of flies live on Earth? • In what order do flies arrive at a dead body? • Where do flies lay their eggs on a body? • Once fly eggs hatch what do they eat? • How do maggots raise the dead body’s temperature? • Where does most of the body's mass go? • Who takes over once the body dries out? • What percent of the original body weight is left behind by the end of the decay stage of decomposition by the insects?

45. Body In The Basement • Read all of page 386 and then answer the following questions: • Why were specimens collected at the scene raised in the laboratory? • Why were data on climatic conditions gathered?

46. Preserving Body Parts! • Parts without muscles such as fingers can be preserved for many hours, while major muscle containing parts such as arms need to be re-attached and revascularized within 6-8 hours to have a viable limb. • Parts should be wrapped with moistened gauze and placed inside a clean or sterile bag floating in ice water.

47. Bellringer • What factors determine how long it takes a fly to find a dead body?

48. Objective • Answer questions to entomology video

49. Forensic Entomology Video • After how many hours is entomology usually the best option to estimate the time of death of a body? • A sampling of which insects, and in what stages, should be taken back to the lab? • Why do forensic scientists preserve half of the larva they take back to the lab and keep half alive? • What other information does an entomologist need to know about the death site? • What two things do forensic scientists use to figure out the exact temperature of the crime scene for the time the body was there?

50. Forensic Entomology • Part One: • https://www.youtube.com/watch?v=VeOtScDxq6s • Part Two: • https://www.youtube.com/watch?v=Ov1tUK8r6sM