2 Forensic EntomologyThe 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.
3 Entomology based on the age of the insect present "Time Since Colonization"number of different techniquesspecies successionlarval weightlarval lengthaccumulated degree hour technique
4 Accumulated Degree Hours Technique used to determine Eclosionperiod 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 hoursADH = Temperature in C x Eclosion of species
5 Accumulated Degree Hour Based on a mean temperature of 20 degrees CFor a blow flyADH = 20 deg C x 21.2 hoursAverage ADH = 424 degree hours for a blow fly to emerge from its eggFor a specific environmental temperature ADH is divided by the temperature
6 Calculating Eclosion using ADH For a specific environmental temperatureAverage ADH is divided by the temperatureAt 25 degrees C 424 hours / 25 = 17 hoursEclosion of a blow fly at 25 C = 17 hours
7 SERIAL KILLERS CASE STUDY 1 OCT 6 Who is the most notorious serial killer to have never been brought to justice?
8 Background 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 KellyFollowing the 5th murder, the killings stopped as suddenly as they began.The question remains: Who was Jack the Ripper?
9 The VictimsEach new murder was more gruesome and violent than the previous one.All five women killed within 1/4 of a mile.
10 Who was Jack the Ripper?There are many theories about the true identity of Jack the Ripper, his actions, and behavior.Let’s discuss some of these theories now.
11 Why did he kill? The Ripper Theories 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.
12 Jack the Ripper CASE STUDY Jack the Ripper Part I
13 ADH ReviewEclosion 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?
15 Life Cycle of the Blow Fly Blow Flies are most commonly the first insects to infest a dead body.Lay eggs around natural body orificesNoseEyesEarsAnusPenisVaginaOpen Wounds (Gun shot, Stab, Puncture wounds)
16 Life Cycle Stages of a Blow Fly 1. Egg2 – 4. Larva5. Pupa6. Adult
17 Life Cycle 1St Stage Eggs 2Nd Stage First Stage Larva hatch from eggsMaggots feed on dead tissue.3rd Stage Second Stage Larva Molts from first stage larva4th Stage Third Stage Larva Molts from second stage larvaMasses of third stage maggots produce enough thermal energy to increase ambient temperature up to 10 deg C
18 Life Cycle 5th Stage Third stage Larva molts into Pupa 6th Stage Pupa develops into adult flyApproximately 2 weeks from egg to adultDepends on species and environmental conditionsTemperature/Exposure/Humidity
19 Oct 8 The Diary of Jack the Ripper Part II Complete the question set.
20 Decomposition of a Body Insects will immediately colonize a body.Bacteria, Fungi, and animalsDepends upon where the body is locatedEnvironmental conditionsSome insects thrive in the sun vs. shady conditionsAlso dependent upon stage of decompositionBeetles will consume bone and cartilageLeakage of body fluids will lead to the disappearance of some insects and the appearance of others.
21 Stages of Decomposition 1. Fresh Stage – blow fliesAnts2. Bloated Stage – putrefaction beginsRove beetles and Carrion beetles3. Active Decay StageMaggots feed around natural orifices of body4. Advanced Decay StageBeetles5. Dry StageCentipedes, millipedes, cockroaches
23 AGENDA OCT 14Objective: Describe the steps used to collect insects from a crime scene.1. Question of the Day2. Hand in “Missing Children” Summary3. Collection of Insects and Applications4. Jack the Ripper Case Study
24 The Body Farm - Decomposition Decomposition of a Pig
25 Investigation and Collection of Insects from a Body 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 maggots4. Collect pupae from body, clothing, hair, soil5. Collect empty pupal cases from body, clothing, and surroundings
26 Investigation and Collection of Insects from a Body 6. Collect adult flies7. Collect beetles8. Collect any other insects at scene9. Collect leaf litter near remains of body if outdoors (enough to fill a coffee can).10. Place all insects in vials with food
27 Labeling and Exclusions 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
28 General Applications Detection of abuse in children Neglect in the elderlyAutomobile/Aircraft accident studiesInterpretation of blood spatter patternsDetermination of time of deathRecovery of human blood from digestive tractToxicological analysis
29 Diary of Jack the Ripper Part II Pay careful attention to the timeline of events and the evidence presented to you.Complete the question set.
30 Accident and Criminal Investigations Insects theorized to be within the top 20 causes of automobile accidentsWhat 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 areasPinpointing the location and areas of travel are of unique importance in some investigations
31 THE RIPPER DIARY Part 3 Jack the Ripper Part III