THE POLICE SURGEON SHOULD ALWAYS ASSUME THAT A DEATH, EVEN FROM APPARENTLY NATURAL CAUSES, IS SUSPICIOUS UNTIL HE CONVINCES HIMSELF OTHERWISE. CERTIFICATION OF THE FACT OF DEATH IS NOT SIMPLE UNTIL VARIOUS SIGNS ARE MEASURED. WHATEVER THE PROXIMATE CAUSE, AT DEATH THERE IS CESSATION OF CIRCULATION, RESPIRATION, AND INNERVATION. THE FIRST SHOULD BE TESTED AT THE SCENE BY FEELING FOR AN ACCESSSIBLE PULSE AND APEX BEAT. POSSIBLE RESPIRATORY MOVEMENT OF CHEST OR ABDOMEN SHOULD BE CAREFULLY OBSERVED. LOSS OF INNERVATION IS DETERMINED BY LACK OF REFLEX ACTIVITY ON TOUCHING THE CORNEA OR SHINING A LIGHT IN THE PUPIL. CLASSIC SIGNS OF DEATH INCLUDE LOSS OF HEAT, THE DEVELOPMENT OF HYPOSTASIS, AND STIFFENING. EACH ELEMENT ASSISTS IN DETERMINING THE TIME OF DEATH. TEMPERATURE SHOULD BE DETERMINED THROUGH USE OF A CHEMICAL, NOT A CLINICAL, THERMOMETER PLACED WELL INSIDE THE RECTUM. HYPOSTASIS IS VISIBLE WITHIN 30 MINUTES OF DEATH, IS MAXIMAL IN 6 TO 10 HOURS, AND BECOMES FIXED AFTER 24 HOURS. WITH REGARD TO STIFFENING, IF A BODY DOES NOT HAVE ANY PERCEPTIBLE RIGOR IT HAS EITHER BEEN DEAD LESS THAN 6 HOURS OR MORE THAN 48 HOURS. AGES AT DEATH OFTEN CORRELATE WITH CAUSES. IN INFANCY, SUDDEN DEATH IN INFANCY SYNDROME IS A COMMON CAUSE, IN ADDITION TO NEGLECT OR CONGENITAL ABNORMALITY. DURING CHILDHOOD, THE MOST COMMON CAUSES ARE COMMUNICABLE DISEASES, SUCH AS MENINGITIS; FATAL INJURY; BATTERING; POISONING; AND CONGENITAL DISORDERS. SUDDEN UNEXPECTED DEATH IN ADOLESCENCE IS UNCOMMON EXCEPT AS THE RESULT OF TRAFFIC ACCIDENTS AND DROWNING. IN ADULTHOOD, EARLY SIGNS OF DEGENERATION APPEAR IN THE FORM OF CORONARY ARTERY DISEASE; SUBARACHNOID HEMORRHAGE, HYPERTENSION, AND MALIGNANCY ARE FREQUENTLY THE CAUSE OF DEATH FOR THIS AGE GROUP. IN OLDER INDIVIDUALS, DEGENERATIVE CHANGES, ESPECIALLY VASCULAR DISEASES, PREDOMINATE. THE MOST COMMON METHODS OF SUICIDE ARE POISONING, DROWNING, HANGING, AND WOUNDING. ACCIDENTS USUALLY FALL INTO THE CATEGORIES OF ROAD TRAFFIC AND INDUSTRIAL. THE POLICE SURGEON MUST DETERMINE WHETHER DEATH WAS CAUSED NATURALLY, OR WAS REALLY SUICIDE, MURDER, OR THE RESULT OF AN ACCIDENT. A GRAPH IS INCLUDED IN THE CHAPTER. (LWM)