Strangulation - how it's done - Godoy Medical Forensics

A police department technique used to subdue aggressors. Many police agencies do not allow it to be used or officers must go through specialized training. In this method, the carotid arteries are obstructed, cutting off blood flow to the brain and rendering the person unconscious within 30 seconds.

The most common method seen in domestic violence cases.
Hands are placed on the throat and commonly obstruct the jugular veins, cutting off blood flow from the brain.
Because the blood is still going to the brain, but not leaving it, the increase in pressure causes the capillaries in the face and brain to burst and petechiae may be visible on the skin above the point of constriction, and on the brain on autopsy.
Petechiae form within 20-30 seconds of sustained obstruction, unconsciousness occurs around 2 minutes, death occurs around 4 minutes. Suffocation offers the same approximate times but petechiae may be generalized throughout the body.
It is important to note that these are average times and intoxication, medical conditions, or variations in physiology may affect the amount of time it takes to produce these effects.

The use of a rope or similar object to cause asphyxia.
In ligature strangulation, it is possible to cut off the jugular veins, carotid arteries and/or collapse the trachea.
If petechiae are present, there is likely to be a defined line where the ligature was positioned (pictured).

The use of a rope or similar object to suspend the body by the neck.
Both hanging and ligature strangulation are likely to have visible signs of the ligature on the neck, but the angle of the marks will be upward in hanging and is more likely to be horizontal in ligature strangulation, unless the position of the perpetrator is above the victim.

Strangulation – how it’s done