Chapter 12 Forensic Entomology © 2012 Cengage Learning. All Rights Reserved

Chapter Summary Forensic entomology is the analysis of insect evidence in legal cases. Insects belong to the phylum Arthropoda, a group of organisms with jointed appendages, segmented bodies, and an exoskeleton. The first documented use of insects to solve a homicide case was in China in AD 1235 Since, scientists have added to the knowledge of insect behavior and life cycle. Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary Insect evidence is valuable in estimating the postmortem interval. There are more than 700,000 known species of insects, but only a few have forensic value. Female blowflies are usually the first insects to colonize a dead body. The extent of decomposition—especially if it is unevenly distributed on the body—provides information for estimating the time (and perhaps manner) of death. Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary Entomologists record and analyze climate and weather information related to the insect samples. Temperature, humidity, and other weather and climate elements affect the insects that colonize remains as well as the progression of the insect life cycle. Processing and preserving insect evidence requires special care, techniques, and materials. Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

Bugs Don’t Lie July 9, 1997 Champaign County, Ohio Stepfather, Kevin Neal, claims stepchildren are missing from their back yard Bodies discovered on September 6th were in the late stages of decomposition Autopsies revealed Maggot infestation Absence of blowflies and screwworms Presence of cheese skipper fly in its 3rd instar stage How were these insects evaluated? Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

Introduction (Obj 12.1, 12.2) Arthropod—an invertebrate Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

History Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

Insects & Forensics (Obj 12.2) Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

Insects 29 orders, or related groups, of insects 2 orders are important to forensics Flies (Diptera) Beetles (Coleoptera) Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

Insects at Work (Obj 12.3, 12.5) Metamorphosis—the maturation process for insects) Eggs Larvae Pupa Adult Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved

Postmortem Interval (Obj 12.4, 12.6) Postmortem Interval—the time elapsed since a person died When longer than 72 hours after death, entomology becomes important Within 48 hours the female blowfly lays eggs in moist areas of the body Forensic Science II: Forensic Entomology, Chapter 12 © 2012 Cengage Learning. All Rights Reserved