Death Investigations
UNIVERSITY OF GUELPH-HUMBER – Death Investigations
Learning Objectives
Understand the kind of information that forensic science can provide in a death investigation.
Understand the role of the coroner or medical examiner in death investigations.
Know the five questions regarding death: who, how, when, where, and by what means.
Grasp the basic investigative sequence involved in a sudden death or homicide investigation.
Explain the circumstances under which a coroner will investigate a death.
Understand when police officers may assume and pronounce death.
Introduction
Investigations of sudden and unexpected deaths are overseen by provincial or territorial chief coroners or chief medical officers (medical examiners, MEs).
Not all jurisdictions require a coroner to hold a medical degree, but medical examiners must have a medical degree.
Coroners have quasi-judicial powers enabling them to conduct inquests; conversely, medical examiners typically rely on another entity to conduct inquests.
Canada displays a combination of medical examiner and coroner systems throughout its death investigations.
When does a Coroner Investigate?
The responsibility to notify a coroner arises when evidence suggests a deceased person died due to:
Violence
Misadventure
Negligence
Misconduct
Malpractice
Unfair means
During or following pregnancy in relevant circumstances
Suddenly and unexpectedly
From disease or sickness without treatment from a qualified medical practitioner
From causes not related to disease
Individuals having any reason to believe a death falls under these categories must report immediately to the coroner or a police officer.
Death to be Reported
Instances where death must be reported include:
Death of an inpatient in a designated institution.
Death of an individual in a long-term care home.
Death of an individual occurring in a detention facility or similar settings.
Any death during detention by or in the custody of a peace officer.
Death resulting from police use of force.
Work-related fatalities at construction or mining sites.
Death of an individual while restrained in psychiatric facilities, hospitals, or secured treatment programs.
Medical Assistance in Dying (MAID).
Powers of the Coroner
The powers granted to a coroner include:
The ability to examine or take possession of any dead body.
Entry and inspection of any location where the body is found or was moved from.
Inspection of places visited by the deceased prior to death.
Extraction of information from records related to the deceased.
Seizure of anything material to the investigation.
Delegation of any or all powers to a qualified medical practitioner or police officer.
Stages in Death Investigation
Death is reported.
The coroner will determine whether to investigate.
Decision on whether an autopsy is necessary; if so, a forensic pathologist is engaged to examine the body and conduct tests.
The forensic pathologist informs the coroner of findings.
The coroner evaluates all information to determine how and why the death occurred.
The regional coroner decides on case review or the need for an inquest.
Mandatory Inquests
Inquests are mandatory if the death involves:
Inmates of psychiatric facilities.
Adult or young offender correctional institutions.
Police custody.
Deaths occurring on construction sites.
Deaths at mines.
Purpose of an Inquest
An inquest aims to establish:
The identity of the deceased.
The circumstances surrounding the deceased’s death (how, when, where, by what means).
The outcomes are recommendations and do not result in charges or assigning blame.
Responsibilities of Police
Police must initially assume the person is alive and offer aid.
They may pronounce death in cases of obvious death (e.g., severe decomposition, rigor mortis, gross injuries).
Immediate notification of the coroner and detailed description of circumstances is essential.
Police should secure the scene and preserve the body location until the coroner arrives.
Accompany the body to the morgue and ensure identification matches that of the reported scene.
Police investigators are expected to attend post-mortem examinations concerning sudden or unexpected deaths.
The Five Questions to Investigate Death
Who died?
Identification of the deceased.
How did they die?
Establishing the cause of death.
When did they die?
Where did they die?
By what means did they die?
Who Died?
Tentative Identification methods include two approaches:
Evidence found on the victim or at the scene (e.g., ID cards, registration).
Forensic analysis of remains to match victims with missing person reports.
Forensic anthropology assists coroners and police in recovering remains.
Taphonomy: the study encompassing all events occurring to the body from death until discovery.
Building a biological profile includes identifying sex, age, ancestry, and stature.
Positive Identification Techniques
Positive identification techniques consist of:
Visual identification.
Fingerprints.
Dental records.
Medical records including X-rays and clinical reports.
DNA analysis.
Circumstantial evidence confirming identity.
How Did They Die?
The medical cause of death is assessed by forensic pathologists, who perform autopsies to determine:
Cause of Death (C.O.D.)
Mechanism and manner of death.
Autopsies involve both external and internal examination and investigation of the victim’s clothing.
Forensic pathologists frequently testify as expert witnesses in related cases.
When Did They Die? - Within 24 to 48 Hours
Estimating the elapsed time since death in the early post-mortem interval involves:
Eye Changes: Dry and cloudy appearance within approximately 24 hours.
Digestion: Amount of food digested can provide a time frame if the last meal time is known.
Algor Mortis: Body cooling follows a predictable rate influenced by the ambient room temperature.
Rigor Mortis: The chemical changes in muscle rigidity occur.
Timeline: Onset within 1-6 hours, complete stiffness occurs at 24-50 hours.
Livor Mortis: The blood pooling leads to lividity; can be indicative of time post-death.
Onset is 30 minutes to 4 hours after death, becoming fixed within 8-12 hours.
When Did They Die? - After 48 Hours
In the later post-mortem interval:
Autocatalysis and Putrefaction: degradation processes start affecting the body.
Forensic Entomology: Analysis of insects can provide timing data, up to 30 days based on maggot development.
Plants: Analyzing flora at the scene can indicate the time of year or conditions of death using pollen and leaf litter studies.
Taphonomy at a Glance
Body temperature at death: 37°C (98.6°F).
**Stages of Decomposition:
Pallor Mortis: onset within 15-20 minutes.
Livor Mortis: becomes fixed between 8-12 hours.
Rigor Mortis: full rigor lasts from 12-36 hours post-death.
Putrefaction/Decomposition: becomes evident after 12-24 hours.
Skeletonization: can take from 1 week to multiple years.
Corneal Clouding: happens quickly within minutes to over 24 hours, depending on whether eyes were open or closed.
Where Did They Die?
In instances of natural deaths and suicides, the body is typically located where the individual died.
Homicides often involve bodies being relocated away from the death scene.
A body being moved or discarded does not automatically indicate homicide; it could stem from accidental death or suicide as well.
How Did They Die? Categorized Causes of Death
Natural Death: Resulting from disease rather than neglect or injury.
Accidental Death: Occurs unexpectedly due to unintentional injuries.
Suicide: Intentional act of ending one’s own life.
Homicide: Deliberate infliction of fatal injuries.
Questions around what constitutes murder versus other types of homicide.
Undetermined: Cases where the cause of death is not clear.
Investigative Techniques
The Death Scene
Use the same investigative principles applied in criminal investigations.
The nature of evidence, required expertise, and adopted procedures may vary.
Death scenes could be indoors or outdoors. The body might be found whole, dismembered, or in various decomposition states.
“Burning Bridges” Theory
Once any action is taken at a scene, the state of the scene is irrevocably altered and cannot be restored.
Actions including body movement, autopsy, burial, or cremation affect the original state.
Common Injuries in Death Investigations
Gunshot wounds.
Stab wounds.
Incised wounds.
Asphyxia deaths (including strangulation, suffocation, hanging, drowning).
Blunt trauma injuries.
Fatalities from fire.
Basic Death Investigations
Maintain an open mind: each death is initially treated as a homicide until evidence shows otherwise.
Eliminate the possibilities of suicide and accidental death; what remains may indicate natural causes or an undetermined start.
Apply Ockham's Razor, where the simplest explanation is often the correct one.
Determine Cause of Death
This determination is solely the pathologist’s responsibility.
Brief the coroner and pathologist on the investigational circumstances.
Use scene photographs or video close-up for valuable reference.
Arrange for a post-mortem examination quickly.
Determine Time of Death
Establish the time of death which assists in eliminating possible suspects associated with the death.
Time of death may often be estimated between the last time the victim was seen alive and when the body was discovered.
Unreliable postmortem artifacts are not typically effective for accurate time estimation.
Reconstruct the Events
Utilize investigative techniques to piece together:
Pre-mortem events: conditions leading to the death.
Peri-mortem events: circumstances of the death.
Post-mortem events: activities following the death.
Interviews, canvasses, tips, and scrutinizing documents such as financial transactions, employment records, and communication logs can yield vital insights regarding the manner of death.
Eliminate Persons of Interest
Evaluate relationships, starting with the individuals closest to the victim:
Family, intimate partners, and friends in order of proximity.
Business associates and neighbors also need assessment for establishing alibis and validating accounts of events.
Similar or Related Events
Investigate surrounding events possibly linked to the death:
Stolen vehicles.
Break and enter incidents.
Noise complaints or suspicious person encounters.
Traffic stops and related disturbances.
Indicators of Homicide
Look for multiple or unusually located wounds, especially defensive wounds.
Signs of struggle or forced entry invite consideration of foul play.
Assess the deceased’s clothing for disturbances or blood evidence.
Evidence related to other individuals at the scene.
Background history related to domestic instability or theft cases associated with the victim.
Indicators of Suicide
Lack of homicide indicators present.
Consider demographic factors like age and gender and situational ones, such as the time of year.
Presence of a suicide note and any motives indicated can guide the investigation.
Indicators of Accidental Death
Absence of indicators denoting homicide or suicide.
Investigate the context and the activities the deceased engaged in just prior to their death.
Gather witness accounts and evaluate potential autoerotic scenarios that could lead to accidental fatalities.
Indicators of Death by Natural Causes
Absence of evidence suggestive of homicide, suicide, or accidental death.
Investigate medical history available for the deceased.
Post-mortem examinations provide critical insights into natural deaths.