Hanging is a form of ligature strangulation, but here the force is applied by the body weight. It is not necessary that the body hangs free, and part of the body could still be in contact with the floor .
Hanging can be an accident or suicide. It is seldom used in murder cases, except in situations of lynching.
The post-mortem signs are usually localised, with a ligature mark on the neck - a localised, friction abrasion, almost similar to that caused by a whip.
It seldom goes right round the neck, except if the knot is a sliding knot. The lowest point or mark is opposite the point of suspension, which is usually on the side of the neck or on the back in the midline. It is seldom under the chin (in other words in the field of vision of the person committing suicide). The knot can also leave a mark on the skin. The neck structures are usually less damaged than with throttling. Hypostasis or post-mortem colour changes can occur in the arms and legs if the body had been hanging for some time (fig 8.5). There are usually no signs of asphyxia as the death is usually due to neurogenic cardiac arrest (vasovagal inhibition).
When a person is executed by hanging the body drops farther than in suicide. There is accordingly severe mechanical disruption of the neck structures, including the joints between the neck vertebrae and the skull, as well as the vertebral column.
In all cases of hanging the rope or cord must be removed in such a manner that the knot stays intact, by cutting through the rope opposite the knot, and then joining the two cut ends with a piece of wire.