FRSC1030 Foundations in Forensic Science Chapter 5

Key Terms from chapter 5

Agonal period

The final stage of dying, characterized by a struggle against death and the physiological dynamics leading up to it. Vital functions such as breathing and circulation are severely compromised, but the body is still attempting to stay alive. It can be caused by disease or trauma, and its duration can vary significantly.

Algor mortis

The body’s cooling after death, assuming the ambient temperature is lower than the body temperature. A nude body exposed to 18-20 degrees Celsius will generally drop around 1.5 degrees every hour for the first 8 hours, but this is a very rough estimate that realistically depends on environmental conditions, clothing, body composition, exposure to water, and humidity. 

Antemortem

The period before death, when a person is living and has not yet entered the dying process.

Asphyxia

A stopped supply of oxygen to the brain, with many possible causes such as manual strangulation or strangulation by ligature.

Autopsy

“To look at oneself”, but really meaning to examine and preform a human dissection, that generally entail the removal of internal organs of the chest, abdomen, and head to check for disease or injury.

Biological death

The death of the last cell

Cause of death

The disease or injury that initiated the lethal chain of events, however brief or prolonged, that led to death. It’s the underlying cause, the one that ultimately caused a person to die, even though there may have been several other complications and contributing factors. Also called proximate cause of death.

Computer-aided tomography (CT)

A non-invasive medical imaging procedure that uses a series of X-rays and computer technology to create detailed cross-sectional images of the inside of a body. The “slices” or images can be combined to create 3D images of organs, bones, and soft tissues, providing more detail than traditional X-rays.

Contact wound

An injury resulting from physical contact between a body and a firearm, when the firearm is pressed directly on the skin when discharged. They are characterized by a muzzle imprint and the presence of soot and gases, blackening of the skin and lacerations.

Coroner

A government agent responsible for death investigations, some being appointed, hired as employees, or elected. No specialized training is required, which can lead to faulty death investigations and missed or undetected crimes.

Decomposition

The degradation of tissues and the general breakdown of the body at microscopic and macroscopic levels.

Equivocal death

Also known as a questionable death, a death for which the circumstances and causes are not obvious and which requires additional information.

Forensic pathologists

Physicians specializing in pathology and the diagnosis of disease, and subspecializing in the borderline area between law and medicine that emphasizes the determination of the cause of death

Hyoid bone

A small bone in the neck, examined for fractures when there is suspected strangulation or asphyxia along with the thyroid gland, the brain to look for swelling, and any bleeding in the neck and throat area

Incised wound

A wound made by sharp objects, such as a knife or razor, that is typically longer than it is deep and has clean-cut edges.

Laceration

A wound or tear in the skin made by blunt objects or blunt force trauma, a deep irregular and jagged cut. The edges might have debris, and are usually bruised and messy.

Lead snowstorm

Bright white spots on an X-ray of a person that was shot, that correspond to bullet fragments.

Ligature

An object used for tying or binding something tightly, that may leave markings on the skin.

Livor mortis

Also called lividity, the discoloration of the body that occurs from the settling of red blood cells after the blood stops circulating. Can be seen within minutes of death when the blood cells have an increased sedimentation rate from disease, but generally develops within an hour or so of death, and becomes fixed about 12 hours after death, then slowly disappears with decomposition after 36 hours.

Manner of death

The circumstances of death, not the cause. Can be described using NASH: Natural, Accidental, Suicide, and Homicide. There is also undetermined / indeterminate death, for when there is not sufficient data to assign one of the four manners of death.

Manual strangulation

Strangulation done with bare hands around the neck, one possible cause of asphyxia

Mechanical trauma

A type of trauma that occurs when the applied physical force exceeds the strength of the tissue to which the force is applied. Can be caused by sharp force, blunt force, gun shots, or asphyxia

Mechanism of death

A biochemical or physiological abnormality produced by the cause of death that is incompatible with life, such as exsanguination or organ failure.

Medical examiners

Licenses physicians, with additional training in pathology, that conduct autopsies and integrate information from a case to make the final determination of the cause, manner, and mechanism of death.

Medicolegal death investigator

The first investigative person to respond to a death scene, who will measure body and environmental temperature. check for rigor mortis and other post-mortem changes, interview family and other people to understand the context of the death. They document and collect evidence and work with other personnel to determine if an autopsy is needed.

Medicolegal investigation of death

Also called death investigation, triggered when a questionable death is reported.

Necropsy

The dissection of animals

Odontology

A medical field that uses dental records for identification based on the notion that each person’s natural dentition, coupled with their dental work, provides a reasonable method for identification. Frequently used in mass casualty events where remains may be fragmented and commingled with debris and other remains.

Perimortem period

The time just before death, around death and immediately after death

Post-mortem

The time after death

Post-mortem interval

The time elapsed since death, usually to describe the time elapsed between an individual’s death and their discovery. It can be estimated using many post-mortem changes, such as rigor-, algor-, and livor-mortis, the temperature of the body, and the stage of decomposition.

Proximate cause of death

The specific injury or disease that started the chain of events leading to a death. Also called cause of death.

Putrefaction

The microbial degradation of organic material, primarily driven by microorganisms, such as those found in the intestinal tract.

Questioned death

Also called an equivocal death, a death for which the circumstances and causes are not obvious and which requires additional information.

Rigor mortis

The stiffening of the muscles that occurs following death, resulting from a chemical reaction when muscle glycogen degrades and is not regenerated. Begins 2-6 hours after death, and will generally disappear after 24 to 36 hours after death, when further decomposition of the muscles leads to their loss of ability to remain rigid. 

Stippling

Also called tattooing, a result of unburned gun powder penetrating the skin around the defect created by the bullet.

Tattooing

Also called stippling, a result of unburned gun powder penetrating the skin around the defect created by the bullet.

Virtual autopsy

Also called a virtopsy, a non-invasive technique that uses imaging technologies like CT scans and MRIs to create a 3D digital reconstruction of a body, allowed for detailed examination of injuries and internal structures without physical dissection.