Hanging - According to Biswas (FMT)

Definition

Classification of Hanging (Biswas)

I. Based on Degree of Suspension

The weight of the head alone (5-6 kg) is sufficient to cause death. Complete hanging is NOT necessary.

II. Based on Position of the Knot

III. Based on Mode / Manner (Dikshit/Biswas combined)

Mechanism / Cause of Death

1. Cerebral ischaemia and anoxia - compression of carotid arteries (only 3.5 kg pressure required)
2. Cerebral venous congestion - compression of jugular veins (only 2 kg pressure required)
3. Airway obstruction - direct compression or upward displacement of root of tongue (requires ~15 kg)
4. Vagal inhibition - pressure on vagus nerve or carotid sinus causing cardiac arrest
5. Fracture/dislocation of cervical spine - mainly in judicial hanging ("hangman's fracture" at C2)
6. Combination of the above

Key fact: Trachea requires 15 kg and vertebral artery requires 16.6 kg of pressure to occlude, whereas carotid arteries are occluded at just 3.5 kg - explaining why death occurs even in partial hanging without complete airway obstruction.

Symptoms (Clinical Features)

1. Flashes of light before eyes
2. Ringing/hissing in ears
3. Intense mental confusion - inability to help oneself
4. Loss of consciousness (within 15 seconds with a thin rope)
5. Stage of convulsions - face distorted and livid, eyes prominent, violent struggling
6. Respiration stops before the heart (heart may continue for 10-15 minutes)

Fatal Period

• Judicial hanging (long drop): Death may be instantaneous due to fracture-dislocation of cervical vertebrae, though the heart may continue for 15-20 minutes
• Suicidal/partial hanging: If spinal cord is intact and airway not completely blocked, 5-8 minutes is the usual fatal period

Ligature Mark in Hanging

Characteristics:

• A furrow/groove on the neck
• Does NOT encircle the neck completely - fades/disappears at the knot (site of suspension)
• Runs obliquely upward toward the knot
• Inverted V-shaped (apex at knot) - in typical hanging
• Located above the thyroid cartilage in 80% cases; at level in 15%; below in 5%
• Pale, yellowish, or yellow-brown, parchment-like due to drying of abraded skin
• No surrounding bruising/abrasion (unlike strangulation)
• The head is always inclined to the side opposite the knot

Factors affecting the ligature mark:

1. Type of ligature material (rope = deep, well-demarcated; soft cloth = shallow/absent)
2. Texture of skin and neck
3. Weight of the body suspended
4. Tightness of the ligature
5. Duration of suspension
6. Position of the knot
7. Slipping of ligature during suspension (may produce double mark)

Postmortem Appearances

External:

• Face: Usually pale; congested and swollen with petechiae if venous obstruction predominates
• Neck: Stretched; head inclined opposite to knot
• Eyes: Prominent (congestion); petechiae in conjunctiva
• Tongue: Turgid, may protrude; exposed part becomes dark brown/black from drying
• Saliva: May dribble from corner of mouth opposite to the knot
• Hands/nails: Cyanosed
• Lividity (Hypostasis): Circumferential on legs, hands, and the skin of the face and neck above the ligature
• Seminal emission / urination / defecation may occur

Internal:

• Ligature mark on section: Muscle and soft tissue below the furrow compressed and pale
• Neck vessels: May show transverse intimal tears of internal carotid artery (Amussat's sign - most classical internal finding)
• Hyoid bone/thyroid cartilage: Fractures uncommon in suicidal hanging (more common in strangulation and judicial hanging); hyoid fracture more common in those above 40 years
• Brain: Congested
• Lungs: Congested, frothy fluid in trachea
• Heart: Right heart distended with dark, fluid blood (asphyxial death pattern)
• Petechial haemorrhages (Tardieu spots) on visceral pleura and pericardium

Medico-legal Aspects of Hanging

Is it suicidal or homicidal?

Important Points:

• Homicidal hanging is very rare; if suspected, look for signs of struggle, other injuries, and scene evidence
• A body can be suspended posthumously after murder to simulate suicide - all external signs of hanging can be produced postmortem within 2 hours of death
• In such cases, internal findings (vital reaction at ligature site on histology, signs of primary cause of death) are key
• In sexual/autoerotic asphyxia, padding may be placed under the noose to allow quick release; pornographic material may be found at scene

Judicial Hanging (Execution)

• Used in India for execution of capital punishment
• Face covered with dark mask; person stands on a platform above trapdoors
• A drop of 5-7 metres (adjusted for weight, build, age) is given
• Causes fracture-dislocation of C2 (axis) - "Hangman's fracture" with transection of the spinal cord