Signs of Death (Dead Signs)

Classification Overview

1. IMMEDIATE SIGNS (Somatic / Clinical Death)

A. Insensibility and Loss of Voluntary Movement / Loss of EEG Rhythm

• Loss of all sensation (touch, pain, temperature) and voluntary motor power
• All reflexes are abolished (including corneal and light reflexes)
• Not conclusive alone - can occur in fainting, vagal inhibition, epilepsy, drowning, electrocution, narcosis
• Confirmatory: flat EEG for a continuous 5 minutes

B. Cessation of Circulation

• Stethoscope placed over the heart apex (left 5th intercostal space)
• Absence of heart sounds for a continuous 5 minutes is acceptable evidence of death
• May be difficult if feeble sounds, thick chest wall, or emphysema
• Confirmed by: flat ECG for 5 continuous minutes
• Historical tests (Magnus test, Icard's test, diaphanous test, fingernail test, heat test) are no longer used

C. Cessation of Respiration

• Stethoscope applied to upper lungs or larynx where faintest breath sounds can be heard
• Complete absence of breath sounds for 5 continuous minutes = proof of death
• Respiration can temporarily cease in: voluntary apnea, Cheyne-Stokes breathing, the drowned, and newborns
• Historical tests (feather test, mirror test, Winslow's test) are obsolete

Suspended Animation (Apparent Death): A state where vital signs are so depressed they cannot be detected by routine examination, yet life continues. Causes include vagal inhibition, drowning, electrocution, narcotic poisoning, hypothermia, cholera. A death certificate must not be issued without EEG and ECG confirmation in doubtful cases.

2. EARLY SIGNS (Molecular / Cellular Death)

A. Algor Mortis (Cooling of the Body)

• After death, heat production stops; heat is lost by conduction, convection, and radiation
• Isothermic phase: rectal temperature does not fall for the first ~45 minutes (residual glycogenolysis + intestinal bacterial metabolism generate some heat)
• Thereafter, cooling follows a sigmoidal pattern - not strictly Newton's law
• Rate: in tropical countries (e.g., India), approximately 0.5-0.7°C/hour; body reaches environmental temperature in ~16-20 hours
• Formula (temperate climates):

  Time since death (hours) = (37.2°C - rectal temperature) ÷ 0.6°C/hour

• Factors accelerating cooling: thin body, wasting illness, cold/windy environment, wet clothing, immersion in water
• Factors delaying cooling: obesity, hot environment, asphyxia, carbon monoxide poisoning, enclosed spaces, heavy clothing, dung heaps

B. Changes in the Eye

1. Corneal opacity: the clear, glistening cornea becomes dry, cloudy and opaque (tears no longer produced)
2. Reduced intraocular tension: eyeballs become flaccid and sink into orbits (appreciated by palpation)
3. Retinal vessel changes: bloodstream becomes dotted, then segmented - the classic "cattle-trucking" pattern; optic disc becomes pale
4. Pupil: usually dilates at time of death, then constricts as rigor mortis develops - NOT a reliable indicator of antemortem state
5. Taches noires: brownish-black discoloration on the exposed sclera between the eyelids, appearing within 3 hours if eyes remain open (due to desiccation, cellular debris, and dust settling)
6. Vitreous potassium: rises steadily after death - useful for PMI estimation

C. Changes in the Skin

• Skin assumes a pale, ashy-white appearance (more noticeable in fair-skinned persons)
• Loses elasticity - postmortem incised wounds may not gape like antemortem wounds
• Lips tend to darken due to drying

D. Postmortem Lividity (Livor Mortis / Hypostasis)

• Discoloration of skin and organs after death due to accumulation of fluid blood in the dependent capillaries and small veins (gravity-dependent staining)
• Begins as a pinkish-red color, normally starts within 30 minutes to 2 hours
• Becomes fully established and fixed (non-blanchable) at approximately 6-12 hours after death
• Color significance:
  • Cherry-red/bright pink: carbon monoxide poisoning, cyanide, cold (refrigerated bodies)
  • Dark blue/purple: asphyxia, drowning
  • Greenish-brown: putrefaction
  • Pale/faint: anemia, profuse external hemorrhage
• Medicolegal importance: If the body was moved after lividity was fixed, the old lividity pattern will remain inconsistent with the new position - indicating body displacement

E. Rigor Mortis

• Stiffening and shortening of muscles due to failure of ATP resynthesis after glycogen depletion
• Mechanism: actin-myosin filaments fuse into a dehydrated stiff gel; muscle pH shifts alkaline → acid (lactic acid accumulation)
• Rigor persists until autolysis of actin-myosin occurs during putrefaction (secondary flaccidity)

• Complete rigor: ~12 hours; persists ~12 hours; passes off in ~12 hours (total ~36 hours)
• In heart: rigor appears within 1 hour (left ventricle more affected due to thicker wall)
• Cutis anserina ("goose skin"): when erector pilae muscles are in rigor - skin appears puckered with hair standing on end

• Cadaveric spasm (instantaneous rigidity at time of death, no primary flaccidity - important in drowning/suicide)
• Cold stiffening (freezing of body fluids)
• Heat stiffening (protein coagulation after exposure to extreme heat)

3. LATE SIGNS (Decomposition / Decay)

1. Putrefaction: bacterial decomposition of tissues, producing gases (H₂S, NH₃, methane), greenish-black discoloration starting at the right iliac fossa (cecum area), bloating, marbling of skin vessels, skin slippage
2. Adipocere formation: saponification of body fat into a waxy, soap-like substance under moist, alkaline, anaerobic conditions - preserves body contours for years
3. Mummification: desiccation of body in dry, hot, well-ventilated conditions - preserves external features

Summary: Time Since Death Estimation

• Parikh's Textbook of Medical Jurisprudence, Forensic Medicine and Toxicology, pp. 175-182
• The Essentials of Forensic Medicine and Toxicology, 36th ed. (2026), pp. 157-162