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FORENSIC ENTOMOLOGY Slide 2 The study of insects and their relationship to time of death. commonly called upon to determine the postmortem interval or "time since death" in homicide investigations. Slide 3 based on the age of the insect present "Time Since Colonization" number of different techniques species succession larval weight larval length accumulated degree hour technique Slide 4 Technique used to determine Eclosion period of time it takes an insect to hatch from a fresh egg. Eclosion times have been tabulated to complete this development in various insect species. In a blow fly, this time has been determined to be 21.2 hours ADH = Temperature in C x Eclosion of species Slide 5 Based on a mean temperature of 20 degrees C For a blow fly ADH = 20 deg C x 21.2 hours Average ADH = 424 degree hours for a blow fly to emerge from its egg For a specific environmental temperature ADH is divided by the temperature Slide 6 For a specific environmental temperature Average ADH is divided by the temperature At 25 degrees C 424 hours / 25 = 17 hours Eclosion of a blow fly at 25 C = 17 hours Slide 7 Who is the most notorious serial killer to have never been brought to justice? Slide 8 Jack the Ripper Brutally murdered 5 women from Aug 31 to Nov 9 of 1888 in Whitechapel, London. Mary Ann Nichols, Annie Chapman, Elizabeth Stride, Catherine Eddowes and Mary Jane Kelly Following the 5 th murder, the killings stopped as suddenly as they began. The question remains: Who was Jack the Ripper? Slide 9 Each new murder was more gruesome and violent than the previous one. All five women killed within 1/4 of a mile. Slide 10 There are many theories about the true identity of Jack the Ripper, his actions, and behavior. Lets discuss some of these theories now. Slide 11 He was a doctor, in the military, or a butcher. He removed various organs and other body parts from his victims. He was a psychopath. They were revenge killings. Slide 12 Jack the Ripper Part I http://www.youtube.com/watch?v=i9Brtq 4nLOM http://www.youtube.com/watch?v=i9Brtq 4nLOM Slide 13 Eclosion for a black blow fly has been determined to be 23 hours. An average ADH for this insect is 424 degree hours. What was the environmental temperature of the crime scene where these insects were collected? Would you expect the temperature to higher or lower than 20 degrees C? WHY? Slide 14 424 deg hours _____________ = Eclosion time Enviro Temp Solve for Enviro Temp. 424 deg-hours Enviro Temp = ____________ = 18.4 deg C 23 hours Slide 15 Blow Flies are most commonly the first insects to infest a dead body. Lay eggs around natural body orifices Nose Eyes Ears Anus Penis Vagina Open Wounds (Gun shot, Stab, Puncture wounds) Slide 16 Stages 1. Egg 2 4. Larva 5. Pupa 6. Adult Slide 17 1 St Stage Eggs 2 Nd Stage First Stage Larva hatch from eggs Maggots feed on dead tissue. 3 rd Stage Second Stage Larva Molts from first stage larva 4 th Stage Third Stage Larva Molts from second stage larva Masses of third stage maggots produce enough thermal energy to increase ambient temperature up to 10 deg C Slide 18 5th Stage Third stage Larva molts into Pupa 6th Stage Pupa develops into adult fly Approximately 2 weeks from egg to adult Depends on species and environmental conditions Temperature/Exposure/Humidity Slide 19 The Diary of Jack the Ripper Part II Complete the question set. http://www.youtube.com/watch?v=eNXT WtcsAnU http://www.youtube.com/watch?v=eNXT WtcsAnU Slide 20 Insects will immediately colonize a body. Bacteria, Fungi, and animals Depends upon where the body is located Environmental conditions Some insects thrive in the sun vs. shady conditions Also dependent upon stage of decomposition Beetles will consume bone and cartilage Leakage of body fluids will lead to the disappearance of some insects and the appearance of others. Slide 21 1. Fresh Stage blow flies Ants 2. Bloated Stage putrefaction begins Rove beetles and Carrion beetles 3. Active Decay Stage Maggots feed around natural orifices of body 4. Advanced Decay Stage Beetles 5. Dry Stage Centipedes, millipedes, cockroaches Slide 22 1.4. 2.5. 3. Slide 23 Objective: Describe the steps used to collect insects from a crime scene. 1. Question of the Day 2. Hand in Missing Children Summary 3. Collection of Insects and Applications 4. Jack the Ripper Case Study Slide 24 http://www.youtube.com/watch?v=V_Siq ND9bNA http://www.youtube.com/watch?v=V_Siq ND9bNA Decomposition of a Pig http://www.youtube.com/watch?v=R1CD 6gNmhr0 http://www.youtube.com/watch?v=R1CD 6gNmhr0 Slide 25 1. Look at fauna and test soil to see if body has been moved. 2. Collect specimens from different areas of the body, clothing, surrounding environment (indoor/outdoor) 3. Collect 100 maggots 4. Collect pupae from body, clothing, hair, soil 5. Collect empty pupal cases from body, clothing, and surroundings Slide 26 6. Collect adult flies 7. Collect beetles 8. Collect any other insects at scene 9. Collect leaf litter near remains of body if outdoors (enough to fill a coffee can). 10. Place all insects in vials with food Slide 27 Keep insects collected from different parts of the body separate from one another. Insects would not be present if the body is wrapped in plastic, buried deep underground, and frozen or freezing temperature/conditions Slide 28 Detection of abuse in children Neglect in the elderly Automobile/Aircraft accident studies Interpretation of blood spatter patterns Determination of time of death Recovery of human blood from digestive tract Toxicological analysis Slide 29 Pay careful attention to the timeline of events and the evidence presented to you. Complete the question set. http://www.youtube.com/watch?v=eNXT WtcsAnU http://www.youtube.com/watch?v=eNXT WtcsAnU Slide 30 Insects theorized to be within the top 20 causes of automobile accidents What evidence would support this statement? Consider an automobile accident. Examination of the fragmented remains of insects that have impacted and lodged onto the front fascia, windshield, and radiator of automobiles. Yields evidence to the probable path of an automobile through particular areas Pinpointing the location and areas of travel are of unique importance in some investigations Slide 31 Jack the Ripper Part III http://www.youtube.com/watch?v=ytsal4 gcwpA http://www.youtube.com/watch?v=ytsal4 gcwpA Slide 32 http://www.youtube.com/watch?v=GCyi czAcRBY http://www.youtube.com/watch?v=GCyi czAcRBY