Homicide vs. Murder Investigation Fundamentals

Death Investigation Basics

• Not all homicides are murders, but all murders are homicides.
• Petechiae: pressure from “strangling” can cause bleeding from the eyes.
• Sudden death and homicide investigations require a thorough understanding of the principles of death investigation.

Cause of Death

• The three vital physiological systems that can cause death are:
  • Respiratory
  • Cardiovascular
  • Central nervous system
• Cessation of functions of these systems will result in death.

Manner of Death

• The five manners of death are:
  • Homicide
  • Suicide
  • Accidental
  • Natural Causes
  • Undetermined

Death Scene Investigation

• The death scene is a crime scene where the same investigative principles apply.
• The scene may be inside or outside, and the body may be intact, dismembered, or decomposed.
• The "Burning Bridges" theory states that once anything is done at a scene, it can never be restored to its original state.

Death Pronouncement

• Only a medical doctor (including coroners) may pronounce death.
• Death may be presumed by anyone in certain circumstances, such as:
  • Decapitation
  • Transection
  • Gross decomposition
  • Grossly charred body
  • Gross outpouring of cranial or visceral contents
  • Gross rigor mortis in a pulseless and apneic patient

Basic Death Investigation Sequence

• Keep an open mind and investigate every death as a homicide until homicide can be eliminated.
• Eliminate suicide, accidental death, and natural causes in that order.
• What is left must be undetermined.

Identification of the Deceased

• Identification of the deceased is a vital part of any death investigation.
• Methods of identification include:
  • Witnesses
  • Location
  • Fingerprints
  • X-rays
  • Dental records
  • DNA

Determining Cause of Death

• Cause of death can only be determined by a pathologist.
• Brief the coroner and pathologist on the known circumstances of the investigation.
• Arrange for a post-mortem examination at the earliest opportunity.

Determining Time of Death

• Determining time of death using post-mortem artifacts is unreliable and inaccurate.
• Time of death may be inferred between the time the victim was last seen alive and the time the deceased victim was discovered.

Investigative Procedures

• Reconstruct events:
  • Pre-mortem
  • Peri-mortem
  • Post-mortem
• Conduct interviews and canvasses.
• Gather evidence to corroborate the facts.
• Eliminate persons of interest from the investigation.
• Establish alibis and corroborate information.

Indicators of Homicide, Suicide, and Accidental Death

• Indicators of homicide include:
  • Multiple or unusually located wounds
  • Defense wounds
  • Disruption of the deceased's clothing
  • Signs of struggle or disturbance
  • Evidence of other persons at the scene
• Indicators of suicide include:
  • Absence of homicide indicators
  • Age
  • Gender
  • Time of year
  • Suicide note
  • Motive
• Indicators of accidental death include:
  • Absence of indicators of homicide and suicide
  • Circumstances of the death
  • Witness accounts
  • Autoerotic deaths

Post-Mortem Physiological Changes

• Post-mortem physiological changes can be used to determine time of death, including:
  • Body temperature (algor mortis)
  • Rigor mortis (12 hours)
  • Livor mortis (blood pooling at the lowest part of the body)
  • Gastric contents
  • Decomposition (entomology)

The Role of the Coroner

• The coroner is responsible for investigating deaths that occur in certain circumstances, including:
  • Violence
  • Misadventure
  • Negligence
  • Misconduct
  • Malpractice
  • During pregnancy or following pregnancy
  • Suddenly and unexpectedly
  • From disease or sickness for which the person was not treated
  • From any cause other than disease
• Mandatory death reporting includes deaths that occur in:
  • Provincial institutions
  • Psychiatric facilities
  • Nursing homes
  • Homes for the aged
• Mandatory inquests are required for deaths that occur in:
  • Psychiatric facilities
  • Adult or young offender correctional institutions
  • Police custody
  • Construction projects
  • Mines

Investigative Powers of a Coroner

• The coroner has the power to:
  • View or take possession of any dead body
  • Enter and inspect places where a dead body is found
  • Inspect and extract information from records or writings relating to the deceased
  • Seize anything that may be material to the investigation

Purpose of a Coroner's Inquest

• The purpose of a coroner's inquest is to determine:
  • Who the deceased was
  • How the deceased came to their death
  • When the deceased came to their death
  • Where the deceased came to their death
  • By what means the deceased came to their death