Forensic Archaeology & Forensic Anthropology. ADJ14 Advanced Criminal Investigations

Transcription

1 Forensic Archaeology & Forensic Anthropology ADJ14 Advanced Criminal Investigations

2 Anthropology & Archaeology Anthropology is the study of the biological and cultural aspects of all humans in all places in all times. Archaeology is the study of human history and prehistory through the excavation of sites and the analysis of artifacts and other physical remains.

3 Introduction to Forensic Archaeology & Forensic Anthropology Forensic Anthropology is the field of study that deals with the analysis of human skeletal remains resulting from unexplained deaths. Experts in the discipline, because of their understanding of skeletal biology, examine human bones with the goal of extracting information about persons represented by skeletal remains and circumstances surrounding death (Byers, 2011). Forensic Archaeology is a subfield of forensic anthropology, and forensic archaeology is the forensic application of archaeological techniques. Archaeology is the study of humans, both modern and ancient. Specifically, forensic archeologists perform the controlled recovery of human remains and other evidence at forensic scenes. Proper archeological procedures generally require significant time and attention to detail, and so the process may seem rather slow to investigators. However, the end result of this effort is the ability to exactly reconstruct the entire scene as it appeared before excavation (Nawracki, 1996).

4 Forensic Anthropology Forensic anthropologists attempt to accomplish 5 main objectives in their work: 1 When soft tissue has deteriorated to the point that demographic characteristics of a body cannot be determined by visual inspection, they attempt to determine ancestry, sex, age, and living height from the skeleton. 2 When there is evidence of traumatic injury (bullet holes, stab wounds, fractures) to human bone, forensic anthropologists attempt to identify the nature of the traumas and their causative agent pertaining to cause and manner of death. 3 Rendering a determination of the postmortem interval. 4 Assist in locating and recovering buried or surface remains in such a manner that all evidence relevant to the forensic investigation is collected. 5 Can provide information useful in obtaining positive identifications of deceased persons.

5 Human Osteology & Odontology All forensic anthropologists must be fully knowledgeable in human osteology and, to a lesser extent, odontology. Human osteology is the study of the bones of the skeleton, including names, placement, articulations, visible features, etc. Odontology is the study of dentition; this entails the recognitio of the deciduous (baby) and permanent teeth, as well as placement in the mouth, major features, and variations. The knowledge must be so extensive that not only can complete skeletons and dental arcades be analyzed for information concerning the decedent, but also skeletons with missing and fragmented bones as well as incomplete dentitions and damaged teeth recognized as human.

6 Human Osteology & Odontology Bones and teeth contain many indicators of the basic demographic characteristics of persons. Sex of individuals can be attributed from traits visible on the skull. Pelvis and long bones can also determine sex. A skeleton also contains features that can be used to evaluate ancestry and age at death, as well as living height.

7 The Human Skeleton The adult human skeleton ordinarily composed of 206 bones. Each bone in the body is given a name as well as a side designation (if paired). (e.g., right humerus, left humerus). Some bones and skeletal structures are actually aggregations of a number of smaller bones; for example, the wrist is composed of 8 separate bones, the skull has 22. With the exception of one bone (the hyoid) all bones connect to, or articulate with, at least one other bone. The standard used in describing the skeleton is the anatomical position.

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9 Anatomical Position Position of the body, either standing or lying, with the arms arranged straight along the side and the palms of the hands facing forward. Legs are extended straight, feet arranged as though they were flat on the ground. There is nomenclature for anatomical (also called cardinal) directions and planes, which are used in investigation discussion relating to skeletons and deceased bodies.

10 Cardinal Directions & Planes Cardinal Directions Superior (Cranial) Inferior (Caudal) Medial Lateral Anterior (Ventral) Posterior (Dorsal) Proximal Distal Up; point or region lying above another point or region Down; point or region lying below another point or region Point or region lying closest to midline of the body Point or region lying away from midline of the body Front; point or region lying closest to front of body Back; point or region lying closest to back of body Point closest to an articular point with body Point farthest from an articular point with body Anatomical Planes Frankfort Sagittal Coronal Transverse Plane that aligns the lower border of the eye with the upper border of the ear opening; also called the Frankfort Horizon Plane; cutting through the body from front to back (divides into left/right halves) Plane; at right angles to the sagittal plane, divides body in front and back halves Plane that divides the body at the waist into upper and lower sections

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12 Skeletal Division The skeleton can be divided into 2 areas for ease of study: Cranial Postcranial. Because of its complexity, the cranial skeleton is often studied as a separate unit. This includes: The skull, The mandible (lower jaw) Ear ossicles. The postcranium (all bones below the skull) is divided into two segments: The axial skeleton and thorax (bones making up the vertebral column & rib cage) The appendicular skeleton (bones of the arms, legs, shoulder, and pelvis)

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14 Cranial Skeleton The skull is composed of 22 outwardly visible bones (3 ear ossicles on each side that cannot be seen easily). Except for the lower jaw, these articular tightly at suture lines, so there is little movement between adjacent bones. Cranium is divided into 4 topical areas: (1) Bones that make up the cranial skeleton and the various prominences and other features visible on their exterior surface (2) Sutures, which separate the bones (3) Landmarks on the cranium (4) Various sinuses within bones of the skull

15 Cranial Skeleton

16 Cranial Skeleton

17 Hyoid Bone A small U-shaped bone suspended in the neck at the same level as the inferior edge of the mandible. In young individuals, it is composed of 3 segments which fuse later in life. Hyoid bone fractures occur within 1/3 rd of homicides by strangulation (manual, ligature, or hanging ). Absence of a hyoid fracture does not rule out homicide or suicide. Size of decedent, age, nature and magnitude of force, nature of instrument all are variables in potential fracture or lack of fracture.

18 Vertebrae 3 types of vertebrae are defined by their location in the spine: Cervical Thoracic Lumbar The cervical vertebrae are the top 7 bones in the spinal column The middle of the vertebral column is usually composed of 12 thoracic vertebrae The lumbar vertebrae are the 5 bottom bones of the spinal column, above the sacrum.

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20 Upper Limbs

21 Overview of Human Dentition All forensic anthropologists must have a basic knowledge of human dentition to properly perform their work. Knowledge must include an understanding of dental anatomy, ability to recognize types and placement of teeth, understanding of how dentition develops, and awareness of variations within teeth. The basic anatomy of a tooth can be seen in the picture:

22 Overview of Human Dentition The basic anatomy of a tooth: Crown part visible above the gum; covered in white enamel Where crown meets the rest of the tooth is the neck Root part of the tooth embedded in the jaw; secured by a ligament The root and crown covered by enamel made up of bonelike material called dentin. Occlusal refers to the chewing surface of teeth.

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25 Summary - Osteology 1. Adult human skeleton normally composed of 206 bones. 2. A number of cardinal directions and planes simplify the process of examining the human body. 3. Important features of the skull include the bones, the sutures that separate these bones, landmarks (used to identify various points and regions on the skull), and the sinuses found within various bones. 4. The axial skeleton is composed of the hyoid, the vertebrae (7 cervical, 12 thoracic, and 5 lumbar), the ribs (12 on each side), the sternum, the right and left scapulae and clavicles, and the pelvis. 5. The pelvis is composed of 4 bones: right and left ossa coxae, the sacrum, and the coccyx. 6. Upper limbs composed of 3 paired long limb bones: humeri, ulnae, and radii 7. Lower limbs composed of 3 paired long limb bones: femora, tibiae, and fibulae, kneecaps (patellae) and ankle and heel, foot, and toes types of teeth in the human mouth: incisors, canines, premolars, and molars.