POSTMORTEM EXAMINATION IS A SET OF PROCEDURES USED BY A MEDICAL EXAMINER, CORONER, OR OTHER QUALIFIED PERSONNEL IN THE INVESTIGATION SURROUNDING CERTAIN TYPES OF DEATHS. THE PROCEDURES INCLUDE EXAMINATION AT THE CRIME SCENE, IDENTIFICATION OF THE BODY, EXTERNAL EXAMINATION OF THE BODY, THE AUTOPSY, AND SUBSEQUENT TECHNICAL EXAMINATIONS. THE PRIMARY PURPOSE OF THE EXAMINATION IS TO DETERMINE THE CAUSE OF DEATH. THE INVESTIGATOR MAY USE THE RESULTS OF AN AUTOPSY TO DETERMINE WHO COMMITTED THE OFFENSE. A MEDICAL EXAMINATION ROUTINE SHOULD BE ESTABLISHED BY ANATOMICAL CONSIDERATIONS, MECHANICAL CONVENIENCE, AND THE GENERAL PRINCIPLE THAT A STRUCTURE SHOULD BE EXAMINED BEFORE IT IS DISTURBED. THE CUSTOMARY ORDER OF EXAMINATION IS EXTERNAL EXAMINATIONS, HEAD AND BRAIN, INCISION OF BODY, THORAX, ABDOMEN, PELVIS, EXTREMITIES, AND EXAMINATION OF VARIOUS REGIONS. MICROSCOPIC STUDIES OF SELECTED PORTIONS OF THE BODY SUPPLEMENT UNAIDED VISUAL EXAMINATIONS. AN IMPORTANT FACTOR IN CRIMINAL INVESTIGATIONS IS DETERMINING THE TIME OF DEATH. IT IS NOT POSSIBLE TO BE EXACT, BUT BODY CONDITIONS INCLUDING TEMPERATURE AND RATE OF COOLING, POSTMORTEM LIVIDITY, RIGOR MORTIS, AND PUTREFACTION, CAN INDICATE THE TIME FRAME OF DEATH. CONCLUSIVE EVIDENCE OF A POISONING CAN BE GAINED THROUGH CHEMICAL ANALYSIS, CONSISTING OF SEPARATION, PURIFICATION, AND IDENTIFICATION. ATTEMPTS TO COVER-UP A HOMICIDE THROUGH A FIRE CAN BE REVEALED BY EXAMINING THE BODY (BODIES ARE EXTREMELY RESISTANT TO DESTRUCTION BY FIRE) FOR SIGNS THAT CAN SHOW WHETHER THE PERSON WAS ALIVE OR DEAD AT THE TIME OF THE FIRE. (RCB)