Introduction to Traumatic Deaths and Forensic Anthropology Human Remains Introduction to Traumatic Deaths and Forensic Anthropology

The Postmortem Interval Postmortem Interval: length of time a person has been deceased Most accurately done if body has been found within the first 24 hours of death Determined using algor, rigor, and/or livor mortis

Algor Mortis: The cooling rate of the body after death After death the body cannot maintain its normal internal temperature of 98.6 degrees F--the temperature begins to even out with that of the surrounding environment The Glaister formula is used in determining how long a body has been deceased This is most accurate within 12 hours

The Glaister formula H=(98.4degrees F-Internal temperature) 1.5 You can figure(using this formula) how long it has been knowing that the body cools generally about 11/2 degrees per hour

Livor Mortis Refers to the pooling of blood in the body after the heart stops Livor mortis is caused by gravity Can indicate the position of the body after death Most evident within 12 hours Does not happen in areas of the body that are touching the ground or have been otherwise constricted

Rigor Mortis Refers to the rigidity of the muscles after death Muscles stiffen and can be noticed within 2-3 hours of death and is gone approximately 30 hours after death leaving the body limp

Cause of Death? The cause of death can be obvious because of wounds to the body Sometimes there are obvious gashes or abnormalities giving scientists clues as to how the person was killed Numerous injuries to the body can make determining cause of death more difficult for a pathologist

Manner of Death? Manner of death refers to how a person died Can either be natural, accidental, homicidal, suicidal, or undetermined Usually determined by situations surrounding the crime and how the body was found

Questionable Traumatic Deaths Require a pathologist to perform an autopsy Traumatic deaths are classified into four categories: Mechanical: strangulation, sharp and blunt force traumas, gunshots Thermal: exposure to extreme heat or cold

Cranial Trauma

Traumatic Death Chemical: death resulting from the use of drugs and poisons (both legal and illegal) Electrical: caused by an electrical charge that is passed through the body Can cause ventricular fibrillation (heart attack)

Mechanical Deaths Divided into major categories: Sharp and Blunt Force Trauma Blunt Force Traumas are further divided into Firearm and Non-firearm Group Firearm Trauma can be divided into Low Velocity and High Velocity Penetrating Traumas include gunshot and stab wounds Non-penetrating Traumas include vehicle collisions and falls

Penetrating Traumas Penetrating traumas occur when applied physical force exceeds the tensile strength of the tissue to which the force is applied Sharp Force Injuries Occur from injuries received from knives, swords, and axes The amount of force needed for sharp force traumas is less than blunt force traumas

Types of Wounds Blunt objects produce lacerations and with rough edges. Sharp objects make wounds with sharp edges called incised wounds. Sometimes you can determine the size of the object that made the wound by the wound, however, such determination is always an educated guess.

Blunt Force Injuries Blunt force injuries most commonly cause death when the brain has been significantly damaged. Blunt force injuries can also cause major trauma to internal organs. Both sharp and blunt force trauma can cause exsanguination Exsanguination: bleeding out because of a major artery breach

Firearm Injuries Firearm injuries are the most common suicidal and homicidal wounds seen in the United States. Firearms can be either rifled weapons or smooth bored weapons. Most firearm deaths are from rifled weapons, such as rifles and handguns. Antique weapons and shotguns are smooth bored weapons.

Firearm Injuries May be classified by the velocity of the projectile The extent of the injury increases as the velocity of the projectile increases Impacts with velocities of over 300 m/s are considered high velocity

Firearm Injuries Penetrating wounds has a entrance wound but no exit wound. Projectiles must be recovered from a body for a penetrating wound to occur.

Firearm Injuries A perforating wound has an entrance wound and an exit wound. Projectiles are not likely to be recovered from this type of injury.

How Firearms Work The force that propels the projectile comes from the gas that is produced by the rapid burning of smokeless powder. The smokeless powder is ignited by the striking of a primer inside of the weapon The smokeless powder burns rapidly producing CO, N2O, CO2, Pb, and Bi. These materials are projected from the barrel and make up GunShot Residue.

Products of Gunshot Wounds Contact or near-contact wounds: Gases and heavy metals are only projected a few inches—producing blackening of the skin Skin will also show variable amounts of laceration because of the gas blown into the wound tears the skin apart Carbon monoxide reacts with hemoglobin to produce a bright red discoloration of the wound

Products of Gunshot Wounds Gunshot wounds to head region: Large lacerations caused by tearing characteristics of the scalp and the reflection of gases by the skull Explosion of the head and evacuation of the brain are common effects in shots that produce large amounts of gas

Products of Gunshot Wounds Intermediate range gunshot wounds: Distance from the barrel to the skin is increased and becomes farther apart Effects of gas diminish and only the unburned powder and the bullet are capable of penetration of the skin Unburned powder that penetrates the skin produces stippling (black tattooing) around the wound

Products of Gunshot Wounds Gunshot wounds produced from a distance: Lack smoke and powder effects, such as soot and stippling Entrance wounds are usually circular in pattern with a rim of skin that is missing The elasticity of skin is important when trying to determine the caliber of the weapon in an entrance wound Usually exit wounds are larger than entrance wounds

Other Blunt Force Injuries Transportation collisions, motor vehicle collisions, and death resulting from accidents Homicidal injuries include lethal head injuries, laceration to internal organs due to beating The most common cause of death is drowning in the blood that has been aspirated into the lungs

Other Blunt Force Injuries Victims that have been beaten usually have defensive wounds on the little finger side of the forearm and hand. Other common injuries: Contusion: accumulation of blood in the tissues outside of the blood vessels Contusions can often leave a pattern of the object used in the beating Hematoma: “blood tumor” or large contusions “Goose eggs” on the head

Chemical Trauma Chemical traumas include deaths that result from the use of drugs and poisons. Contribution of Alcohol Approximately 50% of all chemical trauma deaths have alcohol as a contributing factor. Alcohol is a central nervous system depressant; it slows down reactions and communications from brain to body With enough alcohol, coma will be induced or breathing will slow enough to die

Chemical Trauma Other drugs can produce the same effects as alcohol Barbituates—downers, depressants, etc. Diazepams—valium, tranquilizers, sleeping pills, etc. Opiates—narcotic pain relievers, heroin, etc. Marijuana is not known to ever cause a death on its’ own—usually in conjunction with other drugs

Chemical Trauma Cocaine is a central nervous stimulant High doses can result in seizures, extremely high body temperatures, and palpitations of the heart Carbon monoxide is a common chemical that produces death Carbon monoxide is a colorless, odorless, and explosive gas Deaths related to CO may be accidental, suicidal, or homicidal Death occurs because blood cannot be oxygenated and the body suffocates from lack of oxygen

Chemical Trauma Cyanide Interferes with oxygenation of the brain, acting primarily on the enzymes in the brain Has a distinctive odor—it smells like almonds 50% of the general population can smell cyanide Is a common ingredient in household products and in industry applications

Thermal Trauma Exposure to excessive heat or cold may produce death Hypothermia: excessive cold Hyperthermia: excessive heat Both conditions cause death because of a breakdown in the normal mechanisms that maintain body temperature Diagnosis of these causes of death require the absence of other causes of death along with a history of the environment

Hypothermia Common in individuals that are intoxicated with alcohol Hypothermia can be a cause of death when the temperature is only 41 degrees F Alcohol increases the loss of body heat because of the dilation of blood vessels on the surface of the body

Hyperthermia Common in people in waves of extreme heat Common in infants or animals locked in closed vehicles The inside of a car that reaches 140 degrees F can be fatal in 10 minutes Especially common in elderly adults because the ability to regulate body temperature declines with age

Hyperthermia Can also cause thermal burns with contact with a hot object Can be caused from the exposure to hot liquids Can be caused from flames of hydrocarbon Usually result in multiple organ failure Persons who die at the scenes of fires most commonly succumb from the inhalation of products of combustion, such as carbon monoxide.

Asphyxias Asphyxias are deaths caused by lack of oxygen to the lungs and brain Drowning is death by asphyxiation from immersion in water or other liquid If a victim is conscious while the drowning occurs, water may be found in the lungs and sinus cavities Small organisms called diatoms may be found in the water and may be matched to a water source

Asphyxias If a victim is unconscious while the drowning occurs, water may or may not be found in the lungs and sinus cavities This may be an indication that a person was killed in another location and then placed into a water source

Forensic Anthropology (F.A.) Skeletal Remains

Forensic Anthropology (F.A.) A type of applied physical anthropology that specializes in the human skeletal system for purposes of identifying unknown remains Information gathered from the skeletal remains of an individual is the principal source of information about an unidentified individual

Questions can be Answered Using Forensic Anthropology Are the remains animal or human? Are the remains male or female? What is the age of the victim? What was the manner of death? Natural, accidental, homicidal, suicidal, undetermined What was the cause of death? Millions of possibilities; usually determined by injuries to the body

Forensic Anthropology Requires Knowledge of the Skeleton Skull 11. Fibula Mandible 12. Tibia Clavicle 13. Iliac Crest Sternum 14. Os Pubis Xyphoid Process Humerus Radius Ulna Os Coxae Femur

Animal or Human? Osteology--the study of bones Human and animal bones have very different structures When partial bones are only available, scientists look at the osteons Osteons are the holes in bones that carry blood In animals, they form regular patterns In humans, the patterns are known to be more random

Male or Female? Bones in the male skeleton tend to be larger than those of the female skeleton The os pubis, sacrum, and the ilium of the pelvis are bones that have the most obvious differences between men and women

Male or Female? The ventral arc on the female pelvic bones is also more defined than that of the male pelvic bones

Male or Female?

Male or Female?

Male or Female? Male Female

Age? Growth plates called epiphyses form together and eventually unite with age.

Age? Cranial sutures also form a completely connected skull by a certain age

Age? Scientists use the general age for sutures to fuse and compare that age to how formed together these bones are and can make a general age estimate

Race? Caucasoid: Descriptor for people of European, Middle Eastern, and East Indian Descent Characteristics: Long, narrow nasal aperture A Triangular Palate Oval Eye Orbits Narrow Zygomatic Arches Narrow Mandibles

Race?

Race? Negroid: A descriptor for people of African, Aborigine, and Melanesian decent Characteristics: Wide Nasal Aperture A Rectangular Palate Square Eye Orbits Pronounced Zygomatic Arches Long bones are longer and have greater density

Race?

Race? Mongoloid: Descriptor for people of Asian, Native American, and Polynesian descent Characteristics: Rounded nasal aperture Parabolic palate Rounded eye orbits Wide zygomatic arches Pointed mandibles

Race?

Facial Reconstruction Used when traditional methods of identification are not useful Uses standard tissue thickness and facial muscles to build a new face on a skull The skull and skeleton gives information about age, race, and gender Not totally accurate and is more of an art form based in science

Steps in Facial Reconstruction Establish age, gender, and if possible, race Glue tissue markers to landmarks directly on the skull for tissue thickness

Steps in Facial Reconstruction Mark muscle insertion points and mount markers for thickness of tissue Mount eyes in sockets at the proper depth Apply clay to the skull following the contours, using markers and muscle insertion points Make measurements to determine nose thickness and length and the mouth thickness and width

Steps in Facial Reconstruction Cover the skull with layers of skin and add the details of the face

Facial Reconstruction