Homicide / Death Investigation  << back

Forensic Pathology for Investigators

Length of Seminar: 2 Days
Instructor: Dr. Tracey Corey or William Ralston III, MD

Course Overview:
CAUSE: The cause of death is the injury or disease that begins the process that leads to death. The cause of death may be separated into a proximate cause and an immediate cause. The proximate cause is the initial event and the immediate cause is the last event prior to death. Importantly, the length of time between the proximate and immediate cause does not change the final diagnosis or cause of death as long as there is an unbroken chain of events between the two. The time frame may be minutes, days, or years. An excellent history and investigation are critical in making sure the train of events between the proximate and immediate cause are not broken.

MECHANISM: The Mechanism of death is the biochemical or physiologic abnormality resulting in death. Common mechanisms of sudden death include arrhythmias of the heart, shock, or exsanguinations (bleeding). The mechanism is not the cause of death and should not appear alone on the death certificate. For example, in someone with a gunshot wound to the head, the specific injuries to the brain with resultant swelling (cerebral edema) and bleeding do not need to be included on the death certificate. The cause of death is the gunshot wound to head.

MANNER: The manner of death is the circumstance surrounding the death. Traditionally, the manner is classified as one of the following: homicide, suicide, accident, natural, or undetermined.
The ruling of homicide means one person killed another. It does not imply criminality or intent. This is left to the courts.
The ruling of undetermined is made when there isn’t enough evidence to prove a specific manner. An example is the death of a drug abuser who overdosed on Demerol. The amount in the person’s system was very high and suggestive of suicide, but there was no proof the person intended to commit suicide. The pathologist was not certain whether to call the death an accident or a suicide, so the diagnosis of undetermined was made. Someone can die of a heart attack and the manner still can be homicide. It is a homicide if an assailant points a gun at someone during a robbery and the victim becomes excited and dies of a heart attack. In this circumstance, the assailant had the rotten luck of pointing his gun at someone with a bad heart. The rule is, “you take your victim as you find him.”

PROXIMATE CAUSE: The initial event, such as gunshot wound or blunt trauma to the head.

IMMEDIATE CAUSE: The last event prior to death.

TIME OF DEATH: Post mortem interval determining the time of death and when a body is found decomposition, adipocere and mummification.

BLUNT FORCE TRAUMA: If any injuries not caused by a gun or sharp object. Characteristics injuries of blunt trauma are contusions, abrasions and lacerations.

MOTOR VEHICLE DEATHS: Injuries from impact, sudden deceleration and intrusions by other vehicles, pedestrian injuries, secondary injuries.

THERMAL INJURIES: High-voltage deaths, electrocution, fire deaths, environmental injuries, hyperthermia and hypothermia.

DRUG AND CHEMICAL DEATHS: Toxicology reports, signs and symptoms, drug screen, vitreous humor.

SUDDEN NATURAL DEATHS: Arteriosclerotic, hypertensive, ruptured cerebral aneurysm, pulmonary, central nervous system, respiratory.

FIREARM INJURIES: Gunpowder, range of fire, tight contact, loose contact, entrance wounds, and exit wounds.

SHARP FORCE TRAUMA: Cutting, stabbing and chopping wounds, most victims of sharp force trauma die from bleeding internally or externally.

ASPHYXIA AND DROWNING: Asphyxia means lack of oxygen to the brain. Compression of the neck, suffocation, aspiration, gagging, chemical ingestion and inhalation, autoerotic suffocation, drowning.

DEATHS OF CHILDREN: Battered child syndrome, shaken baby, optic nerve hemorrhage, subdural hemorrhage, subarachnoid hemorrhage, diffuse axonal injury, sudden infant death, suffocation.