Determining the cause of Death

Murder, as defined as the unlawful killing of another human being with intent and generally this state of mind distinguishes murder from other forms of unlawful homicide (such as manslaughter). As the loss of a human being inflicts enormous grief upon the individuals close to the victim, as well as the fact that the commission of a murder deprives the victim of his or her existence, most societies have considered it a most serious crime worthy of the harshest of punishment. A person convicted of murder is typically given a life sentence or even the death penalty  for such an act. A person who commits murder is called a murderer;  the term murderess, meaning a woman who murders, has largely fallen into disuse.

Items found near the scene of a crime

As a cause of death, murder is very low on the list of common causes. According to the  World Health Organisation’s Report, the top 15 causes of death are listed below. These 15 causes of death make up about 58 percent of all deaths.

Cause Percent of total
1. Ischemic heart disease 12.6
2. Cerebrovascular diseases 9.7
3. Lower respiratory infections (e.g., pneumonia) 6.8
4. HIV/ AIDS 4.9
5. Chronic obstructive pulmonary disease 4.8
6. Diarrheal diseases 3.2
7. Tuberculosis 2.7
8. Malaria(tied) 2.2
9.  Cancer of trachea/
bronchus/lung (tied)
2.2
10. Road traffic accidents 2.1
11. Childhood diseases 2.0
12. other unintentional injuries (tied) 1.6
13. Hypertensive heart disease (tied) 1.6
14. Suicide (tied) 1.5
15. Stomach cancer (tied)

At a potential crime scene, a forensic pathologist needs to identify the likely cause of death in order to establish whether a crime has been committed. Suspicious deaths will more often than not turn out to be suicide or accidental such as drug overdose. Medicines like insulin which are taken by diabetics can cause an unexpected drop in glucose levels. If an individual with low blood glucose does not get sugar (food) into their system they can collapse and enter a hypoglycaemic coma. If left untreated this can cause death. In order to identify the cause of death involving medicines and drugs, it is necessary to carry out blood tests.

In some cases, it may be possible to rule out suicide immediately by looking at external evidence. For example, in expending a firearm a fine ‘mist’ of powder is released. As the gun fires it releases a flame of the burning gunpowder exiting the barrel, along with soot and unburned gunpowder particles. If the barrel of the gun is near the victim when the gun fires, the flame can actually burn the person’s clothing and skin. The gunpowder residue and soot also sticks to the person’s clothing and skin. If such powder burns are not present on the victim, the firearm must have been fired by a person other than the victim, so a crime is likely to have been committed. In other situations it is only possible to determine the cause of death by a full autopsy.

In some cases there may be a number of injuries to a deceased individual, and it is necessary to determine which factor actually caused the individual to die. For example, head or spine injuries can be common when people jump into shallow water. A medical examiner can determine if the person died as a result of drowning by checking to see if there is water in the lungs. If the head/spine injury killed the person outright, there will be no water in the lungs.

In a house fire, individuals may be killed as a result of burns, or debris falling on them during the fire, but smoke inhalation is the most common cause. It is often difficult to determine which event happened first, as an individual who has died in a fire may later be burnt by the fire, destroying important medical evidence. Fire has been associated with 3 different types of inhalation injuries. More than a hundred known toxic substances are present in fire smoke. When inhalation injuries are combined with external burns the chance of death can increase significantly. The three types of inhalation injuries are:

1.) Damage from Heat Inhalation:

True lung burn occurs only if you directly breathe in a hot air/flame source, or have high pressure force the heat into you. In most cases, thermal injury is confined to the upper airways, because the trachea usually shields the lung from thermal loads. However, secondary airway involvement can occur after inhalation of steam as it has a greater thermal capacity than dry air. When hot air enters the nose, damage to the mucous membranes can readily transpire as the upper airway acts as a cooling chamber.

2.) Damage from Systemic Toxins:

Systemic Toxins affect our ability to absorb oxygen. If someone is found unconscious or acting confused in the surroundings of an enclosed fire, systemic toxins could be a possible cause. Toxin poisoning can cause permanent damage to organs including the brain. Carbon Monoxide poisoning can appear symptomless up until the point where the victim falls into a coma.

3.) Damage from Smoke Inhalation:

Smoke intoxication is frequently hidden by more visible injuries such as burns as a result of fire. Which in a disaster situation can lead to not receiving the medical attention needed, due to the rescue teams taking care of the more apparent patients. Patients that appear apparently unharmed can collapse due to major smoke inhalation, 60% to 80% of fatalities resulting from burn injuries can be attributed to smoke inhalation.