Forensic Entomology Taxonomy Classification of Things in an

Forensic Entomology

Taxonomy Classification of Things in an Orderly Way We are interested in the phylum, Arthropoda; class, Insecta; order: Diptera (flies) Coleoptera (beetles)

Forensic Entomology Involves the use of insects and other arthropods to aid in legal investigations. Entomology is the study of insects. There are three areas of application: Insect damage to structures Infestation of foodstuffs Insects that inhabit human remains (focus of this chapter)

The Process of Death Algor Mortis: Body cooling rate Hours since death = 98. 4°F – internal body temperature 1. 5 Livor Mortis: skin discoloration caused by pooling of blood Rigor Mortis: rigidity of skeletal muscles Temperature of body Stiffness of body Time since death Warm Not stiff Not dead more than 3 hours Warm Stiff Dead between 3 and 8 hours Cold Stiff Dead between 8 and 36 hours Cold Not stiff Dead for more than 36 hours A pathologist estimates time of death from these factors.

The Process of Death, continued Stage Description Initial or fresh decay (autolysis) The cadaver appears fresh externally but is decomposing internally due to the activities of bacteria present before death (0– 4 days). Putrefaction or bloating The cadaver is swollen by gas produced internally, accompanied by the odor of decaying flesh (4– 10 days). Black putrefaction Flesh of creamy consistency, with exposed body parts black. Body collapses as gases escape. Fluids drain from body. Odor of decay very strong (10– 20 days). Butyric fermentation Cadaver drying out. Some flesh remains at first; cheesy odor from butyric acid (20– 50 days). Dry decay (diagenesis) Cadaver almost dry; slow rate of decay. May mummify (50– 365 days).

Life Cycle of Insects Metamorphosis egg larva (maggot) The life cycle of Musca domestica pupa winged adult

Time of Death Insects arrive at a decomposing body in a particular order (succession) and then complete their life cycle based on the surrounding temperature. By collecting and studying the types of insects found on a body and their metamorphic stage, a forensic entomologist can estimate the time of death.

Insects of Death Diptera First to arrive Blowflies Then Flesh flies Houseflies Flies can arrive within minutes. They lay eggs that hatch to maggots. Maggots feed on soft, mushy body parts. More insects arrive to feed on the body and each other.

Insects of Death, continued Coleoptera In rough order of appearance, from within hours to dry decay: Rove beetle Sexton beetle Clown beetle Dermestid beetle Hide beetle Some beetles feed on the corpse, some on maggots, some on other beetles.

Variables Affecting Metamorphosis Temperature The higher the temperature (within limits), the faster the growth.

Variables Affecting Metamorphosis, continued Habitat Fly species can vary geographically according to climate, season, and habitat. Phormia regina Lucilia illustris For example, the fly pictured on the left prefers shade; the on the right, sunlit areas.

Other Applications of Forensic Entomology Damage to structures, clothing, foodstuffs Location of wounds on a corpse Linking suspect to scene of crime Source of contraband Type of insects can trace vehicle movement Presence of drugs in corpse

Collection of Evidence

Human Remains 15

Human Remains Forensic Anthropology Forensic anthropology is a type of applied anthropology that specializes in the changes and variations in the human skeleton for the purpose of legal inquiry. 16

Human Remains 17

Human Remains Forensic Anthropology, continued A forensic anthropologist may provide basic identification information on skeletonized or badly decomposed remains. From a whole bone or part of a bone, the scientist may be able to determine: • • • An age range Sex Race Approximate height Cause of death, disease, or anomaly 18

Human Remains Osteology is the study of bones. There are 206 bones in an adult human. Function of bones: • Provide structure and rigidity • Protect soft tissue and organs • Serve as an attachment for muscles • Produce blood cells • Serve as a storage area for minerals • Can detoxify the body by removing heavy metals and other foreign elements from the blood 19

Human Remains Estimation of Height The height of a person can be calculated by measuring the length of certain long bones, including the femur, tibia, humerus, and radius. Below are the equations used to determine average measurements for both male and female. (All measurements are in centimeters. ) Male Height, H Female Height, H H = femur 2. 23 + 69. 08 H = tibia 2. 39 + 81. 68 H = humerus 2. 97 + 73. 57 H = radius 3. 65 + 80. 40 H = femur 2. 21 + 61. 41 H = tibia 2. 53 + 72. 57 H = humerus 3. 14 + 64. 97 H = radius 3. 87 + 73. 50 20

Human Remains Age Determination Most accurate estimations are made from: • Teeth • Epiphyses or growth plates • Pubic symphysis • Cranial sutures: The three major cranial sutures appear as distinct lines in youth and gradually close from the inside out. Investigators always use an age range because of the variation in people and how they age. The investigator does not want to eliminate any possibilities for identification. 21

Human Remains Age By Teeth 22

Human Remains Cranial sutures 23

Human Remains Age Determination Using Cranial Sutures Sagittal suture completely closed Male— 26 or older Female— 29 or older Sagittal suture completely open Male—less than 32 Female—less than 35 Complete closure of all three major sutures Male—over 35 Female—over 50 Sagittal suture Lambodial Coronal 24

Human Remains Age Determination Using Basilar Suture Basilar suture Technically known as the synchondrosis sphenooccipitalis, closes in females as young as 14 and in males as young as 16. If the suture is open, the individual is generally considered to be 18 or younger. 25

Human Remains Age Determination In long bones, the diaphysis, or shaft, makes up most of the bone’s length. The epiphyses are found at the ends of the bones; their function is to allow for growth. The epiphyses are good places to look for changes in estimating age. Though all people are different and grow at different rates, there are similarities that allow for generalizations in estimating age. 26

Human Remains Definitions Stage 1: no epiphysis (the growth plate has not formed yet) Stage 2: non-union; the epiphysis and bone are separate Stage 3: partial union; the epiphysis is attached, but a line is visible Stage 4: complete union; the epiphysis is attached and a line is not visible 27

Human Remains The Medial Clavicle in Stages 1– 4 28

Human Remains Age Determination Using Epiphysis Stage of Union of Medial Clavicle Male Female 21 or younger 20 or younger Non-union with separate epiphysis 16– 21 17– 20 Partial union 17– 30 17– 33 21 or older 20 or older Non-union without separate epiphysis Complete union 29

Human Remains Gender Differences in Bones Determination of sex is crucial to the analysis of unidentified human remains. The pelvis offers the most definitive traits. Comparison of three characteristics of the os pubis gives the information used to identify sex. Male Pelvis Female Pelvis 30

Human Remains Gender Identification A. The female (top) has a wider pubic body than the male (bottom). B. The female has a wider subpubic concavity or subpubic angle. 31

Human Remains Gender Identification, continued C. Most females have a ventral arc present. 32

Human Remains Male Female Subpubic Angle 33 18

Human Remains Determine which are male and which are female. 34

Human Remains Gender Differences The rib cage and shoulders of males are generally wider and larger than those of females. In addition, about one person in 20 has an extra rib. This is more common in males than in females. 35

Human Remains Skull Gender Differences 36

Human Remains Gender Differences, continued In males, the index finger is sometimes shorter than the third finger. In females, the index finger is sometimes longer than the third finger. This is not often used as an indicator of gender, as there are many exceptions. Is this a male or female hand according to the above rule? 37

Human Remains Race is difficult to determine from most skeletal remains, especially since pure races are becoming uncommon. An experienced forensic anthropologist can generally place skulls into one of three groups: • Caucasoid—European, Middle Eastern, and Indian descent • Negroid—African, Aborigine, and Melanesian descent • Mongoloid—Asian, Native American, and Polynesian descent 38

Human Remains Race Characteristics Caucasoids—have a long, narrow nasal aperture, a triangular palate, oval orbits, narrow zygomatic arches, and narrow mandibles. Negroids—have a wide nasal aperture, a rectangular palate, square orbits, and more pronounced zygomatic arches. The long bones are longer, and have less curvature and greater density. Mongoloids—have a more rounded nasal aperture, a parabolic palate, rounded orbits, wide zygomatic arches, and more pointed mandibles. 39

Human Remains What differences do you notice among these three skulls? Can you determine race? 40

Human Remains Facial Restoration After determining the sex, age, and race of an individual, facial features can be built upon a skull to assist in identification. Erasers are used to make tissue depths at various points on the skull. Clay is used to build around these markers, and facial features are molded. 41

Human Remains The Body Farm is the nickname of a two-and-a-half-acre research facility in Tennessee developed in 1980 by Bill Bass where bodies are placed in various conditions and allowed to decompose. Its main purpose is to observe and understand the processes and timetable of postmortem decay. Over the years it has helped to improve the ability to determine “time since death” in murder cases. Hic locus est ubi mortui viveuntes docent. “ This is the place where the dead teach the living. ” 42

Human Remains Anthropologist at Work This anthropologist is hard at work dusting away material from these embedded bones. Picture taken at Chicago’s Museum of Natural History 43

Human Remains More Applications Forensic experts may be called upon to give information on the life and death of humans and animals in unique circumstances, including: Mass murder (Oklahoma bombing, plane crashes, World Trade Center) Earlier man (mummies, Iceman, Lindow Man) Historical significance (Holocaust, uncertain death of famous people) Prehistoric animals (dinosaurs) 44

Human Remains Animal Facial Restoration Determining what T. Rex looked like using the bone formation. From this: To this: 45

Forensic Pathology Death Detectives

Forensic Pathologist n Forensic Pathologist - investigates sudden, unnatural, unexplained, or violent deaths. They usually perform autopsies to determine cause of death n 4 yr. Degree + Med School + Residency + Medical Pathology Training (2 years) n Work in hospitals or as medical examiner Kendall/Hunt Publishing Company 47

Pathologist Conclusions n Five Conclusions drawn for investigation: – Natural – Homicide – Suicide – Accident – Undetermined Kendall/Hunt Publishing Company 48

Forensic Pathologist n Way time of death are determined: – Algor Mortis - loss of body heat – Livor Mortis - 0 -12 hours, settling of blood – Rigor Mortis - 24 -36 hours, muscles relax and become rigid – Potassium levels on ocular fluid Kendall/Hunt Publishing Company 49

Livor Mortis – Lividity Kendall/Hunt Publishing Company 50

Rigor Mortis Kendall/Hunt Publishing Company 51

Pathologist v Coroner n Coroner is elected official – no requirements exist, most funeral people – Historically they solved crimes – Power to call grand jury – Being eliminated in other states – Georgia still has position, county decision • Fulton does not have a coroner – Mostly shuffles paperwork, defers to medical examiner’s office Kendall/Hunt Publishing Company 52

When notice to coroner/medical examiners office is required n Death is: – Violent – Suicide – Sudden w/ apparent good health – Unattended by physician – Suspicious, especially under 16 yoa – Under 7 yoa unless expected – Execution – Inmate of state facility Kendall/Hunt Publishing Company 53

When notice to coroner/medical examiners office is required n Once notified they decide if further investigation is needed n Autopsy a possibility – Required in under 7 yoa Kendall/Hunt Publishing Company 54

Autopsies n Means - “see for yourself” n Purpose is to learn the truth about the person's health during life, and how the person really died n 2 types: medical & forensic "Hic locus est ubi mors gaudet succurrere vitae“ "This is the place where death rejoices to teach those who live” Kendall/Hunt Publishing Company 55

Autopsies n Religious Issues: – Orthodox Jews: usually require Rabbi present, very resistant to autopsies – Muslims: also resistant – State has power to ignore religious concerns Kendall/Hunt Publishing Company 56

Autopsies: Method n n n examine the outside of the body is opened using a Y-shaped incision from shoulders to mid-chest and down to the pubic region top of the skull is removed, and the brain is very carefully cut free breastbone and attached rib cartilages are removed chest organs, including the heart and lungs, are Kendall/Hunt inspected Publishing Company 57

Autopsies: Method take blood from the heart to check for bacteria n blood, urine, bile, or even the fluid of the eye used for chemical study and to look for medicine, street drugs, alcohols, and/or poisons n After any organ is removed, the pathologist will save a section in preservative solution n Kendall/Hunt Publishing Company 58

Autopsies: Method n n n n Organs are all weighed Heart is removed Neck organs, large airways, and lungs are removed in one piece Liver is removed and sliced Digestive tract removed then renal/sex organs removed Any suspect organ is inspected closely Kendall/Hunt Publishing Company 59

Autopsies: Method Organs returned to cavity or cremated n Body sewn up, baseball stitch n Head more carefully sewn n Body washed and forwarded as requested by family n Kendall/Hunt Publishing Company 60