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Forensic Entomology

Forensic Entomology

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Forensic Entomology

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  1. Forensic Entomology Joyce Chan Instructor: Mary Villani

  2. Entomology is the study of insects Forensic Entomology is the application of using arthropods in legal investigations It is typically sub-grouped into: Urban, Stored-Product, and Medicolegal What is Forensic Entomology?

  3. Urban: pest infestations in buildings or gardens that may be the basis of litigation between private parties and service providers Urban Entomology

  4. Stored-product: used in litigation over infestation or contamination of commercially distributed foods by insects Stored-Product Entomology

  5. Medicolegal: used in litigation over criminal actions by people, in cases such as murder, rape, suicide, physical abuse, etc. Medicolegal Entomology

  6. History of Forensic Entomology: The Earliest Case • Sung Tz'u (1235 AD) – Chinese “death investigator” • Wrote The Washing Away of Wrongs • First forensic entomology case recorded • A murder by slashing occurred in a village, and the local death investigator was ordered to solve the crime. The investigator had all villagers bring their sickles to one spot and lay them out before the crowd. Flies were attracted to one of the sickles, probably because of invisible remnants of tissue still remaining on it, and the owner subsequently broke down and confessed to the crime.

  7. Insects • Name comes from Latin insectus, meaning “cut into sections,” referring to the segmented bodies of insects • Major group of Arthropods • Most diverse group of animals on Earth • Over 1 million species • Two groups: Apterygota (wingless) and Pterygota (winged)

  8. Means “jointed foot,” all arthropods have jointed legs Largest phylum of animals: includes insects, arachnids, crustaceans, and many others Arthropods

  9. Insects arrive at the scene in a predictable series of progression Used to determine time of death Can be affected by: temperature, sun exposure, location of body, as well as the surrounding environment Faunal Succession

  10. Faunal Succession Chart

  11. First to arrive at the scene Member of the Calliphoridae family Metallic in appearance Usually blue, green, or black 10-12 mm in length Ability to “smell” death 10 miles away First Wave: Blowflies

  12. Part of the second wave Member of the Sarcophagidae family Breed in carrion, dung, or decaying material Some breed in open wounds of mammals Second Wave: Flesh Flies

  13. Member of the Coleoptera family Common names include: larder beetle, hide beetle, carpet beetle, and kharpa beetle Some species cause millions of dollars worth of damage to fibers Life cycle is about 45 days Third Wave: Dermestid Beetles

  14. Later Waves: Mites • Belongs to subclass Acarina • Have existed for over 400 million years • Over 45,000 species of mites • Usually found in warm locations

  15. Scene inspection Weather Data Collection at crime scene Shipment of evidence to lab Analyzed by forensic entomologist Protocol

  16. Scene Inspection Includes observing: • general habitat and surrounding area • surrounding foliage and flora • Sun and shade conditions • Proximity to outdoors if scene is indoors • All information should be noted • Photos should be taken

  17. Ambient air temperature Maggot mass temperature Ground surface temperature Temperature between body and surface Temperature of soil underneath body Weather data from 1-2 weeks prior including rainfall and maximum and minimum temperatures Weather Data Collection

  18. Collection at Crime Scene: Flies and Beetles • Adult Flies and beetles: move quick and disperse when disturbed • Net : regular insect netting • Killing Jar : cotton swabs soaked in ethyl acetate • Ethyl Alcohol: 75% • Label: geographical location, date and hour of collection, case number, location to where body was moved, name of collector (in graphite pencil, placed inside vial. Second exterior label also necessary)

  19. Collection at Crime Scene: Larvae • Search for presence of eggs • Collect largest larvae • Collect representative sample of 50-60 larvae • Place directly in killing solution or ethyl alcohol • To preserve: boil for 30 seconds within 48 hours • Each Maggot mass is treated as separate sites

  20. Collection at Crime Scene: Live Sample • After collection of primary samples, duplicate samples for live shipment • Place in specimen container • Place beef liver or pork meat in moist environment • Seal and create air holes

  21. Collection at the Crime Scene: After Body Removal • Collect preserved and living samples • Collect soil samples • Collect litter samples • Collect 2-3 inches of top soil • All samples placed in cardboard container for shipment

  22. Shipment • All samples should be promptly shipped to forensic entomologist • Overnight express using USPS (US Mail) or United Postal Service (UPS) • Fed Ex and other services do not ship preserved or live insects

  23. Aerial insect nets18” wood handle12” diameter Vials4 dramscrew cap Forceps“feather-touch”thin & flexible metal Equipment and Tools

  24. Books on Forensic Entomology • Forensic Entomology Gennard, Dorothy E. • Entomology and the Law: Flies as Forensic Indicators Greenberg, Bernard • Forensic Entomology Byrd, Jason H., Castner, James L.

  25. Sources • Information • • • • • • • • •

  26. Sources: Images • • • • • • • • • •

  27. Sources: Images • • • • • • • • • • •