Forensic medicine has thoroughly investigated nearly all cases of violent deaths. Here, we will mention only some of the most common types of violence, but it’s crucial to understand that forensic science can reveal much more.
Gunshots
The most common form of homicide is by shooting. Firearms-related incidents are more prevalent in the U.S. and Canada, but the incidence of shootings is rapidly increasing worldwide. It’s said that the exit wound of a bullet is often larger and more irregular than the entry wound, but this is not always the case. It all depends on the nature of the bullet and which part of the body it enters and exits from. The entry wound is larger than the exit wound if the bullet goes through flesh, but this is less common since the bullet often hits bone. When the bullet strikes bone, it may either bounce off and remain in the body, or exit, making the exit wound larger than the entry. If a bullet hits bone, it often deflects in a different direction. The bullet’s trajectory angle can often be determined.
The entry wound can be easily distinguished. If the gun was fired very close to the skin, there will be soot and residue around the wound. If the gun’s muzzle was pressed against the skin when fired, the skin around the wound will be blackened and possibly pinkish due to carbon monoxide emission. The entry wound will have a star-shaped or splintered appearance if fired from a short distance.
In forensic medicine, there are four types of gunshot wounds:
- Contact wound – The gun’s muzzle was applied to the skin at the time of firing.
- Close range – The gun’s muzzle was between 15 and 20 centimeters from the skin at the time of firing.
- Intermediate range – The gun was between 20 centimeters and 1.5 meters away.
- Long range – The gun was more than 1.5 meters away at the time of firing. In the case of a fatal shooting, there is often debate over whether it was a homicide or a suicide.
Obviously, if the bullet was fired from a distance greater than the length of an arm, it’s impossible for it to have been a suicide. Skin discoloration suggests suicide, though foul play can also be a possibility. The location of the entry wound is also important. Suicides rarely shoot themselves in the torso; a headshot can be either homicide or suicide.
Asphyxiation
Death by strangulation is due to asphyxiation, which is the inability to breathe due to the respiratory system being blocked. Strangulation is a common form of murder, as it’s considered clean and easy. Fortunately, in forensic medicine, there are many signs of asphyxiation.
Asphyxiation leads to decreased oxygen and increased carbon dioxide in the blood and tissues, causing the skin to turn a purplish color (known as cyanosis). Blood spots around the mouth and nose, and petechiae (points of bleeding) due to the rupture of small capillary blood vessels, may appear. When a person is being strangled, they often vomit, but it’s important to note that vomiting could have caused the asphyxiation instead of being a consequence of it.
There are forms of asphyxiation, like choking on food, that can occur naturally, so the investigator would have to be sure if the death was accidental or murder. Telltale signs of murder include strangulation marks on the neck or perhaps fibers in the throat and lungs from asphyxiation. A very common form of asphyxiation in forensic pathology practice is drowning. When someone drowns, the respiratory pathways and stomach fill with water, causing death.
If a drowned body is found but has been moved away from the water in which it drowned, the original scene of death can be located by examining the water found in the body. Traces that might be in the water are traceable, and natural water bodies often contain diatoms (microscopic algae; see the image on the right), which can often be located in specific water bodies. If a drowned person is found in a lake or river, it often raises the question of whether the death was accidental or murder.
People who drown wearing swimwear usually drown by accident, though this is not always the case. People who commit suicide often remove certain clothing items beforehand. If a person is found drowned in shallow water, it is almost certainly a case of homicide, although disabled or ill people may not always be able to save themselves in shallow water. All these aspects should be considered when determining whether a death by asphyxiation was accidental or intentional.
Stab wounds
In forensic medicine, stabbing has always been a very common form of murder. A single stab can cause very little damage, but depending on where it penetrates the body, it can be fatal. Stabbings are associated with knives, but they can also be inflicted with blunter objects, like closed scissors or a poker. We can usually tell what type of instrument was used to stab the victim by observing the wound itself. If the wound is small and clean, no more than a slit, then it’s clear that something very sharp, like a knife, was used.
When the wound is larger and more irregular, it was inflicted by a blunter object. We can usually measure the length of the instrument used by measuring the depth of the wound itself. But how do we know if a stab was homicidal or suicidal? Suicides by stabbing are becoming less frequent today, due to the simpler options of drugs and firearms available, but they still occur. Cuts on the wrists and throat are often associated with suicide, while stabs in the back are obviously unlikely.
In suicide, a person rarely kills themselves with a clean stab or cut to the wrist or throat; there are usually several tentative cuts before the final, fatal cut is made. We can also determine if a cut or stab was made by another person by observing its position. If a person has been stabbed in the back, it’s highly unlikely, if not impossible, that they inflicted the wound on themselves. By examining the cuts, we can look at the direction they move to know who made them. There are some directions in which a cut could move that would be impossible for the victim to inflict on themselves, indicating murder.
