- Slides: 14
What is forensic anthropology? • Forensic anthropology is the identification of skeletal, badly decomposed, or otherwise unidentified human remains • Forensic anthropologists frequently work in conjunction with forensic pathologists, odontologists, and homicide investigators to identify a decedent, discover evidence of foul play, and/or the postmortem interval.
Why study bones? • bones often survive the process of decay and provide the main evidence for the human form after death
What information can a forensic anthropologist provide about the deceased? • forensic anthropologists work to suggest the age, sex, ancestry, stature, and unique features of a decedent from the skeleton • When skeletalized remains are discovered, one needs to establish first if the bones are human • They can also in certain cases determine the cause of death
Employment as a Forensic Anthropologist • Employment as a Forensic Anthropologist is as varied as there are crimes, people and places • After the attacks on September 11, 2001, Forensic Anthropologists were deployed to a base in Delaware to begin the tedious process of identifying bone fragments and teeth. • They may be called upon to identify bones and bone fragments sitting in boxes in universities and museums.
The Human Skeleton
Determining Sex and Race • Male Female Size Large Small Architecture Rugged Smooth Palate Larger, Broader, UShaped Small, tends to be a parabola Supraorbital Margin Rounded Sharp Large Small Mstoid a. Process
Determining Age – The best bet in determining the age of a sub-adult skeleton is examination of the teeth and jaw, when present.
Calculating Height and Weight Stature 3. 26 x (humerus) + 62. 10 = stature +/4. 43 cm 3. 42 x (radius) + 81. 56 = stature +/-4. 30 3. 26 x (ulna) + 78. 29 = stature +/-4. 42 Weight Wt (in lbs) = 4. 4 x (stature in inches) - 143
Estimating Time of Death • The first question to be asked and probably the most difficult to answer is "how long has it been dead? “ • Bones do not decay as skin and soft tissue do, but they are subject to weathering and scatter (taphonomy). • Animal scattering of bones can destroy the context of the crime scene and gnaw marks destroy actual bone • If a body is buried, insects cannot get at it, but micro -organisms can. The acidity of soil will have an effect on bone.
Time of Death Continued… • Condition of bone depends on the type of burial or exposure along with temperature. • When a body is left on the surface, insect activity will begin immediately and within 2 weeks the body will be partially skeletalized, completely skeletalized within 8 months. • If buried, it will take between 1 and 2 years to become completely skeletalized and in arid areas may become mummified. • The number and types of bones available at the scene indicates the amount of time the body has been in that spot, i. e. smaller bones get lost first.
Manner and Cause of Death • Manner of death refers to the 5 possibilities: homicide, suicide, accidental, natural and unknown. • Cause of death refers to injury or disease, or combination, that results in death and could take months/years. • Determining the cause of death is easier with a fleshed body and very difficult with the flesh and organs gone. • Taking X-rays of the skeletal material is very important. • Damage from metal objects leaves fragmented metal or metal shavings and saw tooth shavings will show up bright white on X-ray. Bullets will leave fragments of lead.
Types of Fractures Type of Fracture Characteristics Complete broken all the way through Incomplete crack; not all the way Comminuted piece not with the bone Linear pressure on skull, stress released by cracking; soft blunt weapon Stellate star-shaped piece missing; hard blunt weapon Depressed usually with stellate, piece pressed in; hard blunt object, sometimes sharp weapon Broken Hyoid if not adult, not fused; may indicate strangulation Timing near cracks do not cross prior cracks; indicate order of attack